XL2000: How to Programmatically Make Sure That Only Numbers Are Entered in a Column

This article contains a sample Microsoft Visual Basic for Applications Sub procedure (macro) that you can use to ensure that only a certain type of data entry occurs. The macro in this article requires a user to enter only numbers in a specific column on a worksheet.

NOTE: The Validation command in the Data menu provides the same functionality as the sample macros in this article and has an expanded range of restrictions and validation message options.

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 Microsoft Advisory Services. For more information, visit these Microsoft Web sites:

Microsoft Certified Partners - https://partner.microsoft.com/global/30000104

Microsoft Advisory Services - http://support.microsoft.com/gp/advisoryservice

For more information about the support options that are available and about how to contact Microsoft, visit the following Microsoft Web site:http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS To create and run a sample Visual Basic macro that can restrict the data type in a spreadsheet column, use the steps in the following example.

This sample macro restricts the data in column "C" (column 3) of worksheet 1 to numbers only.

1. Start Excel, and then Press ALT+F11 to start the Visual Basic editor.
2. On the Insert menu, click Module.
3. In the module sheet, type the following code:

   Sub Auto_Open()
       Sheets("Sheet1").OnEntry = "numbers"
   End Sub
   
   Sub numbers()
       If ActiveCell.Column = 3 And Not IsNumeric(ActiveCell.Value) Then
           MsgBox "Enter a number."
           ActiveCell.Value = ""  ' Clears contents of active cell.
       End If
   End Sub
   					

4. Press ALT+F11 to return to Excel.
5. On the Tools menu, point to Macro, and then click Macros.
6. In the Macro name box, click Auto_Open, and then click Run.
7. In cell C1, type C, and then press ENTER.
   
   The entry disappears and a message box returns "Enter a number".

For more information about validating data in a worksheet, click Microsoft Excel Help on the Help menu, type specify the valid entries for cells in the Office Assistant or the Answer Wizard, and then click Search to view the topic.