Die Ultimative Software-P…i Collection 1996 & 1997/Die Ultimative Software-Pakete CD-ROM fur Atari Collection 1996 & 1997.iso/f/finanzen/checkbal.fld/checkbal.doc

Text File | 1996-09-18 | 19.4 KB | 545 lines

                                William Blair
                              2608 Adela Avenue
                              Orlando, FL 32826
                               [phone]

                           Check Balancer Program


     I had my Atari 8-bit computer for four years, and one of the things I

used it for most often was to balance my checkbook.  When I moved up to the

16-bit Atari's, I sold my 8-bitter, much to my later regret.  One of the

things I missed most was the program that I had used in balancing my

checkbook, especially since it made what usually was a tedious task into a

simple process.

     It soon occurred to me, however, that the ST computer would be even

better for that sort of thing.  The GEM interface would definitely make a

program more user-friendly, and the speed-up in sorting and searching would

certainly be a plus.  So I took it upon my self to write a checkbook

balancing program of my own.  And this is what came from the effort.

     The program itself is written in Modula-2, a language designed by the

same person who designed Pascal, Dr. Nickolas Worth.  It allows a great

amount of modularity (hence the name) and enables fast development.  This is

the first program that I have written on the ST computer, and the first time

I have used Modula-2.  Still, I was able to finish the program in about 72

man-hours.  This includes initial design, programming and debugging.  A very

nice language, Modula-2.

A Note on Dialogs

     When entering dollar amounts into the program, you will find that

leading zeros must be entered.  I realise that this can get irritating,

however, I chose this method for two good reasons.  First of all, I wanted to

use the TOS input routines for the dialogs, so that it would limit the type

of characters to be entered, and would save me from having to write the input

routine myself.  It is difficult to intercept the text entered in a dialog,

and I wanted the only characters to be accepted for the amount input to be

numbers.  Also, I was trying to save time in writing this program since I had

a (self-imposed) deadline.  The second reason for using the TOS input

handling routines is that I wanted to have the decimal point present in the

input area because I thought it improved the look of the dialog.  It

shouldn't cause too many problems.

     Also, all alphabetic information entered during the dialogs must be

uppercase.  It data is entered in lowercase it won't show up on the screen

and this could be confusing.  Just make sure that uppercase is enabled before

entering data.

Using the Program

     The program was developed to allow the user to enter all withdrawals,

deposits, and checks written on a bank account into a file.  The entries are

placed in the file ordered on the date the transaction occurred.  The program

allows the entries to be searched using a number of criteria, and also will

assist in balancing the account.  These are described in more detail below.

Note that no menu selections are enabled until a file has been loaded, or at

least until a filename has been given and initial file data entered.

     This initial file information consists of the user's name, address,

city, state, year, and current amount in bank account.  The name and address

information isn't essential and doesn't have to be entered, but it improves

the look of the program.  The current bank account balance must be entered,

however.  Just get the amount from the last bank statement received.

     There is a limit on the greatest value that can be displayed in the

dialogs.  This is $99999.99, or for negative numbers, $-9999.99.  This is

because I only allowed seven characters for displaying the numbers in the

dialogs.  This won't cause any problems for the most part, since few people

have deposits or withdrawal amounts in those quantities.  However, if by some

chance such a large number does occur, a message will appear stating that the

number can't be displayed, and the program will continue.  Dispite the fact

that the number isn't displayed, it is still valid in memory, and will be

used in the calculations done.

The File Menu

     This menu contains the file commands.  They are used to load, save, and

delete a file, as well as quit the program.

     Load - This is about the only menu selection enabled when the program

first comes up.  It is necessary during the first use of the program to use

LOAD so that some program information can be entered.  When this is selected,

the program checks to see if there is any valid data in memory.  If so, it

asks the user if it is okay to delete the current data before loading a new

file.  If the user selects YES, the program deletes the data.  Then the user

will be asked for a filename using the standard GEM item selector.  Selecting

CANCEL will abort the selection.  If a filename is entered, the program

checks to see if the file exists.  If it does, the data is loaded into

memory.  If not, this is when a dialog box will open that will ask for some

initial data from the user as described above.  Clicking on the exit button

will save the information within the program.

     Save - This command will save the data currently in memory, then will

return to the program to allow further changes to be entered.

     Close - Like SAVE, this command will save the data currently in memory.

However, it also deletes the data in memory to allow a new file to be loaded.

     Delete - This command allows a file to be deleted.  It asks for

confirmation before executing.

     Quit - This command exits the program.

The Entry Menu

     This menu has the commands used to enter data about checks, withdrawals,

and deposits into memory.  It uses dialogs to help speed things up as well as

make entry easier.

     Enter Checks - This command allows the user to enter checks.  It opens a

dialog which looks similar to a check form, and allows entry of date, check

number, payee, check amount, and a short memo line.  Clicking on the "Enter

Check" button will enter the data into memory and allow a new check to be

entered.  The check number will be automatically incremented each time.

After all checks have been entered, clicking on the "Quit" button will exit

the check form.

     Enter Withdrawals - This command allows the entering of all withdrawals

that are not checks.  It allows entry of date, withdrawal amount and a short

memo line.  As above, clicking on the "Enter Entry" button will enter the

data into memory, while clicking on the "Quit" button will exit the form.

     Enter Deposits - This is similar to the "Enter Withdrawals" form but is

used for deposits into a bank account.

     Make New Year File - This command is used at the end of the current year

to build a file for the next year containing all the entries that hadn't been

cancelled.  It also carries over the name, address, current balance, and

increments the year.  This allows the user to avoid having to re-enter this

information at the end of a year.  This command will delete the entries

currently in memory during the search, so make sure any new entries have been

saved before using it.  A message will come up to insure this has been done.

     Note that after the user exits a form, a dialog will come up showing the

current balance left in the account after the checks, withdrawals, and

deposits have been entered.  This dialog is exited by clicking on the "Okay"

button.  If the current balance is too large to be displayed within the seven

character limitation, an error dialog will come up instead.

The Search Menu


     This menu allows the user to define parameters for searching and

printing, and to search and print using those parameters. As noted above, all

data must be entered in uppercase.

     Enter Parameters - This command opens a dialog that will allow the user

to specify an number of search criteria.  These will allow searching and

printing based on date, check number, payee (or substring thereof), amount,

and memo (or substring thereof).  The data is checked for validity after the

dialog is exited by clicking the "Okay" button.

     When the dialog first comes up, there will be default values for each of

the search criteria.  If the user wishes to return to these default values

after they have been modified, all that is necessary is to press the escape

key for that entry.  When the dialog is exited, it will place the default

values in any entry that it finds empty.  This is necessary for the payee and

memo string searches since the default is "All", and this can't be entered

from the keyboard since it contains lowercase letters.

     Search Entries - When this command is selected, the program will ask if

the user wishes the include the withdrawal and deposit entries in the search.

This is so a user that wishes to see data relating to checks only can do so.

The program will then search the list of entries using the parameters

specified in the above command.  A "Searching" message will show on the

screen during the search process.  After all entries have been located that

match the search criteria, a window will open to display the first entry.  To

examine the entries, simply click the up and down arrows of the window, and

the entries will be displayed one by one.  The search command can be exited

by closing the window.

     Note that when the window is open the Options menu selections become

enabled.  These will allow the entry in the window to be deleted, cancelled,

or edited.  More information on how these are used can be found below.

     Print Entries - This command will print the list of entries that match

the search parameters.  A "Searching" message will display during the search

process, then the program will start printing the entries.  This is a simple

routine that doesn't allow the print format to be modified.  It simply allows

the user to make a printout of his entries for his records.

     The printing can be stopped any time by hitting any key.  This will stop

the printing and return control to the program.  Also, if an error occurs

with the printer, the program will stop and display an error message to the

user.

The Review Menu

     This menu contains the commands that are used to balance the checkbook.

     Review Entries - This command will open a window that will allow the

user to review the entries in memory.  The entries can be displayed forward

and backward as in the search window by clicking the up and down arrows of

the window.  The entries can also be reviewed by clicking the left and right

arrows of the window.  This will display the entry that begins the next

month.  For example, if an entry for January is displayed in the window,

clicking on the right arrow will skip over all entries until it finds the

first entry of the next month, which is February.  If there is no entry for

February, it will display the first entry for the month of March, and so on.

This allows a speedy method of skipping to the end of the year, or jumping

over many of entries at a time.

     As above, this command will enable the selections in the Options menu,

and will allow the user to delete, cancel, or edit the entry currently

displayed in the window.  The command is exited by closing the window.

     Figure Balance - This command will determine if the entries stored in

memory, and the entries on the bank statement match.  It will first ask for

the current balance that is shown on the bank statement.  Then it will

display a dialog showing the following information: the bank statement

balance, the amount of uncancelled withdrawals, the difference between the

two (the subtotal), the amount of uncancelled deposits, the addition of the

subtotal and the deposits (the calculated total), the program's current

total, and the difference between the calculated total and the program's

total.  This difference should be zero if the entries in the memory and the

bank statement match.  If they do not match, the entries in memory are

probably wrong, and should be compared with the bank statement to make sure

the amounts are correct, and that all entries are present.  An error message

will appear if the account is unbalanced.

The Options Menu

     This menu contains the commands the affect the entries that are

displayed in the search and review windows.  They are disabled until the

windows are opened.

     Delete Entry - This command will delete an entry from the list.  It will

prompt for a verification before deleting, since once the entry is deleted it

is gone forever.  If the last entry in memory is deleted, the display window

will close since there are no more entries to display.

     Cancel Entry - This command will mark an entry as cancelled.  This means

that the entry was found on the bank statement, and that the bank has taken

it into account in calculating the balance on the statement.  Since the bank

has taken it into account, the program must also, and this command tells it

to do so.  However, an entry can be uncancelled by using the command a second

time, so any errors in cancelling can be repaired.

     Edit Entry - This command allows the currently displayed entry to be

edited.  A form will open displaying the current data and allowing the user

to change it.  The form used is the same one used when the entry was first

entered.  Clicking on the "Enter Entry" button will update the changes to

memory, while clicking on the "Quit" button will ignore the changes.

     There is a difference between editing entries displayed in the search

window, and editing entries displayed in the review window.  In the review

window, when an entry has been edited and entered, the modified entry will be

displayed in the window.  In the search window, the window will close after

the entry has been edited.  This is because once an entry has been modified,

there is a chance that it no longer follows the search criteria, and

therefore should not be displayed.  The list of entries must be searched

again to bring the window back.

Balancing the Checkbook

     As briefly describe above, this program will allow the user to balance

his checkbook.  The method used to do this is rather simple.

     First, enter all of the transactions that occur during the month.  Then,

when the bank statement arrives, go through the entries one by one, and check

to see if they appear on the bank statement. If they do, then cancel the

entries using the CANCEL command.  After all of the entries have been

checked, select the FIGURE BALANCE command.  Enter the ending balance that is

on the statement.  The program will show the various amounts used to

determine if the entries in memory match the entries on the bank statement.

If all goes well, they will match and the program will state that the account

is balanced.  If there is an error, an error message will be displayed.

     If an error occurs, this usually means that one or more of the entries

in memory have invalid amounts, or that an entry is missing.  It is possible

that the error is with the bank statement, but this is highly unlikely.  The

only thing that can be done is to review the entries, and check the amounts

against the bank statement to insure they are correct.  This will usually

solve the problem.

Program Design and Implementation

     The program listing is commented well enough so that the logic can be

followed without much trouble.  However, there are some design considerations

that were important to the development of the program that may be of some

interest to other programmers, especially those unfamiliar with pointers or

linked lists.

     When I first decided to write the program, I wanted to have the entry

list sorted using the date.  One of the ways I could have done this is to

have sorted the list after every entry.  This would become very time

consuming, so it couldn't be used.  I also had a problem in that I didn't

want to allocate a large amount of memory all at once to be used for the

entries, because no matter how large I made the memory block, it would put a

limiting factor on the amount of data that could be entered.  For these two

reasons I decided to use a linked list using pointers for holding the data

for the entries.  Since pointers were used to link the entries, the entries

could be sorted after every data entry by simply inserting the entry into the

correct place in the list, without having to move the locations of the other

entries.  This structure also eliminated the need to allocate a large memory

area, since I could allocate memory for each entry as it was needed, and

deallocated it when the entry was deleted.  Thus the linked list structure

was very useful for this implementation.

     For those programmers that aren't familiar with linked lists and

pointers, the routines in the program can be very useful.  One of the

convenient aspects of using pointers in data representations is that the

algorithms for insertion and deletion into and from a linked list are

standard, and don't have to be modified to be used in a new program.  The

algorithms used in this program came from a data structures book,

Fundamentals of Data Structures, by E. Horowitz and S. Sahni.  Except for

some additional code unrelated to the linked list that I added, the

algorithms are exactly as they appeared in the book.

     A linked list is also used for the search routine.  This is because I

needed a fast and easy way to display the entries matching the search

parameters.  Searching for the next entry every time an arrow was clicked

would be too time consuming.  So I sacrificed some extra memory to generate a

list of the entries that matched the parameters.  This list is built during

the "Searching..." message, which is why it doesn't appear on the screen for

very long if the entry list is small (doesn't take much time to search the

entries).  Once the list is built, it is a simple matter of displaying them.

After the search window is closed, the entries in the list are deleted, and

the memory is freed.  By the way, this same procedure is used in the print

routine.

That's It

     That pretty much covers the check balancer program.  I tried to put as

much error checking as I could, as well as spending time trying to make sure

everything worked the way it was supposed to work.  Hopefully no serious bugs

are hiding in it.  I hope you enjoy using it.