Address Book Navigation Buttons

The Address Book application displays the navigation buttons at the bottom of the Web page. You can use the navigation buttons to navigate around the data in the grid display, by selecting either the first or last row of data, or rows adjacent to the current selection.

The following code defines the navigation buttons. These HTML statements appear before the VBScript section of the program. Copy and paste these controls following the comment tag which refers to them.

<INPUT TYPE=BUTTON NAME="First" 		VALUE="First">
<INPUT TYPE=BUTTON NAME="Prev" 		VALUE="Previous">
<INPUT TYPE=BUTTON NAME="Next"		VALUE="Next">
<INPUT TYPE=BUTTON NAME="Last"		VALUE="Last">

HTML uses the INPUT tag to define a form element, such as a button, option button, check box, or text. You use the TYPE parameter to specify the type of form element, which in this case is a button. The NAME parameter defines what the button will be called in code. The VALUE parameter specifies the labels associated with the button (First, Previous, Next, and Last) that are displayed on the page.

When a user clicks a button, an event is generated, and VBScript activates the appropriate navigation Sub procedure.

Navigation Sub Procedures

The Address Book application contains several procedures that allow users to click the First, Next, Previous, and Last buttons to move around the data. To enable movement, you can specify the method of the RDSIE3.DataControl object (SControl) to the type of movement you want. The method differs for each navigation button.

For example, clicking the First button activates the VBScript First_OnClick Sub procedure. The procedure executes a MoveFirst method, which makes the first row of data the current selection. Clicking the Last button activates the Last_OnClick Sub procedure, which invokes the MoveLast method, making the last row of data the current selection. The remaining navigation buttons work in a similar fashion. Copy and paste this code within the <Script> </Script> tags.

' Move to the first record in the bound recordset.
Sub First_OnClick
  	SControl.MoveFirst
End Sub

' Move to the next record from the current position 
' in the bound recordset.
Sub Next_OnClick
  	If SControl.EOF Then	'cannot move beyond bottom record
		SControl.MoveFirst 
		SControl.MoveNext
		Exit Sub
	End If	

	SControl.MoveNext

End Sub

' Move to the previous record from the current position in the bound 
' recordset.
Sub Prev_OnClick
  	If SControl.BOF Then	'cannot move beyond top record
		SControl.MoveLast	'Get out of BOF buffer
		SControl.MovePrevious
		Exit Sub
	End If
	SControl.MovePrevious

End Sub

' Move to the last record in the bound recordset.
Sub Last_OnClick
  	SControl.MoveLast
End Sub