Microsoft KB Archive/177271

= WD97: Converted WordBasic On Error Statements May Fail =

Article ID: 177271

Article Last Modified on 1/22/2007

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APPLIES TO


 * Microsoft Word 97 Standard Edition

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This article was previously published under Q177271





SYMPTOMS
When you run a Microsoft Visual Basic for Applications procedure or macro that was converted from a WordBasic procedure or macro that contained error trapping, the error trap is ignored though it worked as expected when run in WordBasic.



CAUSE
Microsoft provides programming examples for illustration only, without warranty either expressed or implied, including, but not limited to, the implied warranties of merchantability and/or fitness for a particular purpose. This article assumes that you are familiar with the programming language being demonstrated and the tools used to create and debug procedures. Microsoft support professionals can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific needs. If you have limited programming experience, you may want to contact a Microsoft Certified Partner or the Microsoft fee-based consulting line at (800) 936-5200. For more information about Microsoft Certified Partners, please visit the following Microsoft Web site:

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http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

By design, the On Error statement in Visual Basic works differently from WordBasic. In Visual Basic, On Error is not cleared when an error occurs, while in WordBasic, the On Error statement is cleared, the error trap is reset, and your code continues to run.

Therefore, the following sample converted WordBasic code fails when an error occurs the second time. Sub Main ' Clear error trap. Set error trap. On Error GoTo -1: On Error GoTo ErrorTrap ' Loop 10 times. For i = 1 To 10 ' Artificially raise an error. Err.Raise 5 ErrorTrap: ' Decision tree based on error returned. If Err.Number = 0 Then ' If no error occurred, do this... count_ = count_ + 1 Else ' Else, if error occurred, do this... Err.Number = 0 End If     Next End Sub



RESOLUTION
To resolve this issue, make the On Error statement the first statement inside the loop.

Sub Main ' Loop 10 times. For i = 1 To 10 ' Clear error trap. Set error trap. On Error GoTo -1: On Error GoTo ErrorTrap ' Artificially raise an error. Err.Raise 5 ErrorTrap: ' Decision tree based on error returned. If Err.Number = 0 Then ' If no error occurred, do this... count_ = count_ + 1 Else ' Else if error occurred, do this... Err.Number = 0 End If     Next End Sub In this example, the Err.Raise statement artificially raises an error for demonstration purposes. When the error occurs and the next iteration of the loop occurs, the "On Error GoTo -1" statement clears the error trap and the "On Error GoTo ErrorTrap" statement resets the error trap. The loop continues to process without interruption until it completes the designated number of iterations (10).



STATUS
Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article.

