Simply Multiplication on SubForm field using VBA

[DB2010MN26]

Have a subform that I use to edit my Trade ticket table. I want my Total Cost field to update to (Units * Price) + Commision on the After Update event for my Units, Price and Commision fields. Heres my code:



Private Sub Units_AfterUpdate()
Total Cost = (Price * Units) + Commision
End Sub


I get the following error;

Compile Error: Sub or function not defined.


I'm very new to using VBA in access so I'm sure its something very simple my missing. Please advise....

Thanks

[pbaldy]

Presuming those are all field names, the inadvisable space would require the first one to be bracketed.