Drop down menu from subform

[Burden]

I was wondering if anyone can help me with this one as i am really
loosing the will to live.

I have a main form which i wish to log PCB numbers. On that form i
have two subform's, one which is called Board Information and one that
is called Software Information. I have got the Board Information
subform to link not a problem to the main record and only show the
board revisions for the main record, but then when it comes to the
software subform i hit this problem.

I would like a drop down field on the software subform to select the
board revision number from the Board Information subform. This has to
be linked. Now all i can do at the moment is make the drop down show
me all the board revision's that have been enetered and not the ones
that are tied to the main form record like the other subform does.

Where am i going wrong?

I would like to thank any body in advance for this as i said i am
loosing the will to live here.

 

[Burden]

Sorted it by running a query.

Sorry i missed the most obvious.