I am tring to set a Contol Source for an abject as:
Thisform.MyVar1 + Thisform.MyVar2

I have ongoing problems trying to do this, and sometimes it seems to work and sometimes not. I've tried:
=Thisform.MyVar1 + Thisform.MyVar2 for indtance and sometimes get message:
The DataSource for this object must be a variable reference.

I'm wondering what is the exact syntax for what I am trying to do ?

Regards,

Gerard