MODIFYING THE INPUT CHARACTERISTICS

     RTTT is defined as follows:

        R_DISPLAY =
        RECORD
             WHITESPACE  : CHAR;
             ALLOWESC    : BOOLEAN;
             BEEP        : BOOLEAN;
             INSERT      : BOOLEAN;
             BEGCURSOR   : BOOLEAN;
             ALLOWNULL   : BOOLEAN;
             RIGHTJUSTIFY: BOOLEAN;
             ERASEDEFAULT: BOOLEAN;
             SUPPRESSZERO: BOOLEAN;
             FCOL        : BYTE;
             BCOL        : BYTE;
             HIFCOL      : BYTE;
             HIBCOL      : BYTE;
             LOFCOL      : BYTE;
             LOBCOL      : BYTE;
             PFCOL       : BYTE;
             PBCOL       : BYTE;
             BOXFCOL     : BYTE;
             BOXBCOL     : BYTE;
             MSG_FCOL    : BYTE;
             MSG_BCOL    : BYTE;
             MSG_LINE    : BYTE;
             END_CHARS   : SET OF CHAR;
             REALDP      : BYTE;
        END;

     WhiteSpace - the character that is used to fill the null part of the
     field, i.e. demarcates the input field area. Default: chr(250), a
     small dot.

     AllowEsc - set to true if the user is allowed to press Esc and
     terminate input. Default: true.

     Beep - set to true if the system should beep when the user types an
     invalid character. Default: true.

     Insert - set to true if the input session should be initially set in
     insert mode. Default: false.

     BegCursor - set to true if the cursor should be initially placed in
     the first position. Otherwise the cursor is placed at the end of the
     input field. Default: false.

     AllowNull - set to true if the user can return a null value, i.e. an
     empty field. This variable is used in number input to suppress range
     checking when the user has null input. Default: true.

     RightJustify - set to true if the field should be displayed to the
     right of the field when the input is complete. Default: false.

     EraseDefault - set to true if the default field value is to be erased
     when the first key pressed by the user is alphanumeric. Default:
     false.

     SuppressZero - set to true to suppress the display of a zero default.
     Default: true.

     FCol - normal foreground color of the input field. Default: black.

     BCol - normal background color of the input field. Default: lightgray.

     HiFCol - highlighted foreground color in Read_Select procedure.
     Default: black on color systems, white on monochrome.

     HiBCol - highlighted background color in Read_Select procedure.
     Default: lightgray on color systems, black on monochrome.

     LoFCol - normal foreground color in Read_Select procedure. Default:
     lightgray.

     LoBCol - normal background color in Read_Select procedure. Default:
     black.

     PFCol - prompt foreground color. Default: white.

     PBCol - prompt background color. Default: black.

     BoxFCol - box foreground color. Default: white.

     BoxBCol - box background color. Default: black.

     Msg_FCol - validation message foreground color. Default: lightred on
     color systems and white on monochrome.

     Msg_BCol - validation message background color. Default: black.

     Msg_Line - the line number to display the validation error message. If
     a value of zero is used, the message is displayed immediately below
     the field. Default: 0.

     End_Chars - this variable is defined as a set of char. Update this
     variable with the characters/key combinations that will end the field
     input session. Note that the last character pressed by the user is
     always stored in the global variable R_Char. This concept is discussed
     further in the next section. Default: [#13], i.e. Enter.

     RealDp - this field identifies the number of decimal places for
     Read_Real. Default: 2.