WD97: Run-Time Error 5 Using Mid(), Left(), or Right() Function

• Microsoft Word 97 for Windows

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

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   http://www.microsoft.com/support/supportnet/refguide/default.asp

NOTE: In Word 2.0 for Windows, a negative value in the count argument 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(<string>, <start> [, <length>])

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

   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

RESOLUTION

To keep this error from ocurring, first test the length of the string, as in the following 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

REFERENCES

For more information about the Mid, Right, or Left functions, 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:

   ARTICLE-ID: Q176476
   TITLE     : OFF: Office Assistant Not Answering Visual Basic Questions

   ARTICLE-ID: Q163435
   TITLE     : VBA: Programming Resources for Visual Basic for
               Applications