Microsoft KB Archive/181103

= WD98: Error Message Using Mid, Left or Right Function =

Article ID: 181103

Article Last Modified on 10/4/2002

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APPLIES TO


 * Microsoft Word 98 for Macintosh

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This article was previously published under Q181103



For a Microsoft Word 2002 version of this article, see 290969.



SYMPTOMS
When you use the Mid, Right or Left functions, you may receive the following error message:

Run-time error '5': "Invalid procedure call or argument"



CAUSE
Microsoft provides examples of Visual Basic for Applications procedures 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. The Visual Basic procedures in this article are provided 'as is' and Microsoft does not guarantee that they can be used in all situations. While Microsoft support professionals can help explain the functionality of a particular macro, they will not modify these examples to provide added functionality, nor will they help you construct macros to meet your specific needs. If you have limited programming experience, you may want to consult one of the Microsoft Solution Providers. Solution Providers offer a wide range of fee-based services, including creating custom macros. For more information about Microsoft Solution Providers, call Microsoft Customer Information Service at (800) 426-9400.

This problem occurs when the length parameter for the statement is negative.

NOTE: In Word 2.0 for Windows, a negative value in the count parameter of the Mid$, Right$ or Left$ functions is ignored and does not generate an error.

The Mid function returns a portion of a text string starting at a given character position. The syntax for the command is

Mid(, [, ])

where is the text string to search, is the character position from which to start, and is the number of characters to return. If no parameter is specified, or if there are fewer than characters in the text, the function returns all the characters from the position to the end of the string.

The following sample macro illustrates the error message described in the "Symptoms" section of this article: Sub ErrorOccurs Dim Test As String Test = Mid("hello", 1, -1) MsgBox Test End Sub The following sample macro returns the error because the length of the string variable Test minus one is a negative number (0 - 1 = -1): Sub ErrorOccurs Dim Test As String Dim ReturnText As String Test = "" ' Empty string, could be passed as an empty dialog ' variable, for example. ReturnText = Mid(Test, Len(Test) - 1) End Sub NOTE: Word version 2.0 for Windows ignores a -1 value for the parameter. So in Word 2.0 all the characters from the first character position to the end of the string are displayed in the message box. In the first example, the string "hello" is displayed.



RESOLUTION
To keep this error from occurring, first test the length of the string. For example: Sub ErrorDoesNotOccur Dim Test As String Dim ReturnText As String ' Empty string, could be passed as an empty dialog ' variable, for example. Test = "" ' Test the length of the string to ensure ' that subtracting 1 from the length leaves ' at least 1 character. If Len(Test) - 1 > 0 then ReturnText = Mid(Test, Len(Test) - 1) End If  End Sub



MORE INFORMATION
For more information about the Mid, Right or Left Functions/Statements, click the Office Assistant while in the Visual Basic Editor, type Returning Strings from Functions, click Search, and then click to view "Returning Strings from Functions."

NOTE: If the Assistant is hidden, click the Office Assistant button on the Standard toolbar. If the Assistant is not able to answer your query, please see the following article in the Microsoft Knowledge Base:

176476 OFF: Office Assistant Not Answering Visual Basic Questions

