Filter Form records shown using varCriteria

I have an unbound form with 9 fields - 1 xext, 1xYes/No, 7xCombo boxes.  After extensive trawling though EE I decided to use the solution explained in http://www.experts-exchange.com/Microsoft/Development/MS_Access/Q_21582815.html by Harfang which I have amended (as far as I'm able) with my own specifics.  

When the user has entered/selected data (or not) and clicks the OK button I would like it to open the form frmPolicy which is based on the query forFrmPolicy.

The button to Clear the form before entering data works fine.  
However, on clicking OK I just get a message like:   ContactID=7 AND ProviderID=30 AND PolicyPrint=-1
Presumably indicating that it's got the selected data form the form but not doing anything with it.  Right?  

The solution feels so close I can almost smell it!  So what have I missed?
Here's my version of the code:

Option Compare Database

Option Explicit

Private Sub cmdClear_Click()
   ContactID = Null
   ProviderID = Null
   ProductID = Null
   PolicyStatusID = Null
   Kfdreference = Null
   PolicyFundFormatID = Null
   AdviserID = Null
   ParaplannerID = Null
   PolicyPrint = Yes
   ContactID.SetFocus
End Sub

Private Sub cmdQuery_Click()

    Dim varCriteria As Variant

    varCriteria = Null
        If Not IsNull(ContactID) Then _
        varCriteria = varCriteria + " AND " & BuildCriteria("ContactID", dbLong, ContactID)
    If Not IsNull(ProviderID) Then _
        varCriteria = varCriteria + " AND " & BuildCriteria("ProviderID", dbLong, ProviderID)
    If Not IsNull(ProductID) Then _
        varCriteria = varCriteria + " AND " & BuildCriteria("ProductID", dbLong, ProductID)
    If Not IsNull(PolicyStatusID) Then _
        varCriteria = varCriteria + " AND " & BuildCriteria("PolicyStatusID", dbLong, PolicyStatusID)
    If Not IsNull(Kfdreference) Then _
        varCriteria = varCriteria + " AND " & BuildCriteria("Kfdreference", dbText, Kfdreference)
    If Not IsNull(PolicyFundFormatID) Then _
        varCriteria = varCriteria + " AND " & BuildCriteria("PolicyFundFormatID", dbLong, PolicyFundFormatID)
    If Not IsNull(AdviserID) Then _
        varCriteria = varCriteria + " AND " & BuildCriteria("AdviserID", dbLong, AdviserID)
    If Not IsNull(ParaplannerID) Then _
        varCriteria = varCriteria + " AND " & BuildCriteria("ParaplannerID", dbLong, ParaplannerID)
    If Not IsNull(PolicyPrint) Then _
        varCriteria = varCriteria + " AND " & BuildCriteria("PolicyPrint", dbBoolean, PolicyPrint)


    MsgBox Nz(varCriteria, "No Criteria selected - All Records will be shown")

    'Exit Sub
   
    ' store into a query definition for later use:
    CurrentDb.QueryDefs("qselTemp").SQL = "SELECT * FROM forFrmPolicy" & " WHERE " + varCriteria & ";"
   
    ' open a report:
    ' DoCmd.OpenReport "rptPolicies", acViewPreview, WhereCondition:=Nz(varCriteria)

    ' filter an open form:
    Forms!frmPolicy.Filter = Nz(varCriteria)
    Forms!frmPolicy.FilterOn = Not IsNull(varCriteria)

End Sub