Any Reason Why IsNumeric() Fails On A Number?

Question

I currently have this line of code which has been working for the past 6 months:

If IsNumeric(txtProductID.Text) Then
   ...do stuff
Else
   Dim msg As String = "Error!"
End If

All of the sudden, no matter what kind of entry is put in txtProductID (including plain numbers), it fails! Is there reason for me to be going crazy over this?

Answer 1

ugh... i'm an idiot... thanks for your help guys, but apparently i was clearing my whole form before accepting input, so "" will never pass as "IsNumeric". Please don't look at this question again. I feel ill.

Thanks again for your help.