ASP - Check form felt

Dim MyVar, MyCheck
MyVar = 53                    ' Assign a value.
MyCheck = IsNumeric(MyVar)    ' Returns True.
MyVar = "459.95"              ' Assign a value.
MyCheck = IsNumeric(MyVar)    ' Returns True.
MyVar = "45 Help"            ' Assign a value.
MyCheck = IsNumeric(MyVar)    ' Returns False.

if NOT IsNumeric(Request.Form("dit_felt")) then
  'ikke et tal
end if

lukketid?