It appears I can set the 'Source Object' property of a subform at design time ( i.e Query.qryReferralsByClient ) but I would like to override this at runtime, and pass my query a variable using WHERE clause( WHERE Client_ID='4' for example ) How do I do this ?

Can't you just use the Link Master and Link Child field options? I'm assuming the main form recordset has a field with the Client_ID value and when you move through this recordset you want to display the relevant referrals from your qryReferralsByClient query in the subform!

Thank you. I'm about to try that ( again ).

It says it 'can't build a link between unbound forms' ( I'm using a DoCmd method in the VBA code) for the main form. I know wehn you use the wizard it 'links the Main Form and subform at design time, but I need more flexibility over the recordsets. Hope this makes sense. Here's the main form's code ...

DoCmd.OpenForm "frmAfAIS(test)", , qrySelectClientsByAdvocate, "Advocate_ID=" & rs.Fields("Advocate_ID")

This loads the required records, I now wish to select only records based on a common field 'Client_ID' to both recordsets ( which doesn't actually show on the form ) to display in the subform datasheet view. Thanks.