Getting value of open form using VBA

[AceBK]

I am struggling to get the value off of an open form into my current form using VBA. I am trying:

Me.InvoiceNumber = Forms!Invoices!InvoiceNumber

But it is not working. Both fields have the same type, Number - Long Integer.

Any ideas what I am doing wrong?

 

[Galaxiom]

"Not working" doesn't tell us much.

What does happen?