Subform Change - Run-time error 2101

[Cheshire101]

I have a main form with a sub form on it that I would like to change depending on a drop down field selected on the main form, below is the code I was trying but can not make it work.
Dim varX

varX = DLookup("txtPNJobCode", "tblPartNumber", "txtPNPartNo = '" & Me.txtInspPNumber & "'")

If varX = "1322" Then
Me.SubForm.SourceObject = frmPAInspSub
Me.SubForm.LinkChildFields = txtPANPartNumber
Me.SubForm.LinkMasterFields = txtInspPNumber
ElseIf varX = "1318" Then
Me.SubForm.SourceObject = frmGDInspSub
Me.SubForm.LinkChildFields = txtGDSNPartNumber
Me.SubForm.LinkMasterFields = txtInspPNumber
End If
Error received: The setting you entered isn't valid for this property. (Run-time error '2101')


The lookup is working fine the line of code being highlighting for debugging is the link field lines.

[RuralGuy]

Try:

If varX = "1322" Then
   Me.SubForm.SourceObject = frmPAInspSub
   Me.SubForm.LinkChildFields = """txtPANPartNumber"""
   Me.SubForm.LinkMasterFields = """txtInspPNumber"""
ElseIf varX = "1318" Then
   Me.SubForm.SourceObject = frmGDInspSub
   Me.SubForm.LinkChildFields = """txtGDSNPartNumber"""
   Me.SubForm.LinkMasterFields = """txtInspPNumber"""
End If

[Cheshire101]

Ok changed the code to this:
Select Case DLookup("txtPNJobCode", "tblPartNumber", "txtPNPartNo = '" & Me.txtPNumber & "'")
Case "1322"
Me.SubForm.SourceObject = "frmPAInspSub"
Me.SubForm.LinkChildFields = ""
Me.SubForm.LinkMasterFields = ""
Me.SubForm.LinkChildFields = "txtPANPartNumber"
Me.SubForm.LinkMasterFields = "txtPNumber"
Case "1318"
Me.SubForm.SourceObject = "frmGDInspSub"
Me.SubForm.LinkChildFields = ""
Me.SubForm.LinkMasterFields = ""
Me.SubForm.LinkChildFields = "txtGDSNPartNumber"
Me.SubForm.LinkMasterFields = "txtPNumber"
End Select

Which works fine unless the user changes the field and the second time the case is different, then the system gives an error for a parameter value of the other case for the link field information.
I tried yours but still same problem.

[Cheshire101]

I think I need some kind of reset on before update but I can not think of how to do this.