fonction:IsNumeric
exemple:
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.