Combo Box in form to select record in Sub-Form

[Johnthelleader]

I am sorry if this is old hat but I am pulling my hair out on this. I hope it is something simple.

I have a form; record source is Table "Invoices" The sub-form record source is the same.

Using the wizzard, I created a combo box whose source was the table "Invoices" field called Law Firm. I have selected the third option to look up a value.
So when a firm is selected from the list in the combo box, it brings up all the details in the sub-form.
However this is not happening.

Any suggestions as to what I could be doing wrong?

 

[MStef]

You don't need a Main form and subform, (enough 1 form).
Let wizard to make a combo box for you,(in form header).
In "COMBO BOX WIZARD" form choose a point "Find a record on my form
based on the value I selected in my combo box". Follow wizard.