Link 2 Combo Boxes

Hi,

I'm trying to link 2 combo boxes, so that the values displayed in the second combo are dependant on what is selected in the first combo.

I've referred to previous posts, in particular http://forums.aspfree.com/t32756/s.html&highlight=linking+combo, but I'm having the same problem...

The Row Source for my first combo reads as:
SELECT tblGroup.Group FROM tblGroup;

The Row Source for my second combo reads as:
SELECT [tblPart].[Group], [tblPart].[PartNo] FROM [tblPart] WHERE ((([tblPart].[Group])=[Forms]![frmQuotations]![qryEquipment subform].Form![cboGroup]));

I also have this code under the first combo's after_update event:
Private Sub cboGroup_AfterUpdate()

cboPartID.Requery
Me.cboPartID.SetFocus

End Sub

However, this brings up the 'Enter Parameter Value' msgbox asking for the cboGroup value.

Can anyone suggest anything I could be doing wrong?

Also, can someone confirm where I would find the subform's name...? Strange question I know, but I did not create this database, and under the subforms properties there isn't a field that specifically says 'Name'. Record source is 'qryEquipment', and caption is 'qryEquipment subform'. The form is also called 'qryEquipment subform' under the Forms tab.

Thanks in advance!