Try :
txtFirstNo.ControlSource = Worksheets("dbInfo").Range("E21").address
as ControlSource requires a string.

NickHK

"Ömer Ayzan" wrote in message
...
Friends I'm using Excel 2003 and on msform I have a simple textbox named
txtFirstNo. Sometimes (I could not repeat problem bymyself) I get the error
message 'Could not set the ControlSource property. Invalid property value'
to an assignment statement:
txtFirstNo.ControlSource = dbInfo!E21. I have other text boxes whose
control source set manually. They work perfectly fine. But this one gives me
trouble.
Any Idea why?

Ömer Ayzan