Query By Multiple Selection List Box

so i have two listboxes that have the values i want for the query parameters. I slightly modified one code i found so that i can query using one of them, however i cannot figure out how to get the second listbox to put criteria into another field. The working code i'm using is:

Private Sub Command_Click()
On Error GoTo Err_Command_Click

On Error GoTo Err_Handler
Dim varItem As Variant
Dim strCriteria As String
Dim strSQL As String


For Each varItem In Me.PartyBox.ItemsSelected
strCriteria = strCriteria & "counterparties.counterparty =" & Chr(34) & Me.PartyBox.ItemData(varItem) & Chr(34) & " Or "
Next varItem


strCriteria = Left(strCriteria, Len(strCriteria) - 4)

strSQL = "SELECT counterparties.[Counterparty Entity], Fund.[Fund Name], products.Product, combine.[Available?] " & _
"FROM products INNER JOIN (Fund INNER JOIN (counterparties INNER JOIN combine ON counterparties.[Counterparty ID] = combine.[company id]) ON Fund.[Fund ID] = combine.[fund id]) ON products.[Product ID] = combine.[product id] " & _
"WHERE " & strCriteria


CurrentDb.QueryDefs("1").SQL = strSQL


DoCmd.OpenQuery "1"

Exit_Handler:
Exit Sub

Err_Handler:
If Err.Number = 5 Then
MsgBox "Must Make A Selection First", , "Make A Selection First"
Exit Sub
Else
MsgBox Err.Number & " " & Err.Description
Resume Exit_Handler
End If


Dim stDocName As String
stDocName = "combqry"
DoCmd.OpenQuery stDocName, acNormal, acEdit

Exit_Command_Click:
Exit Sub

Err_Command_Click:
MsgBox Err.Description
Resume Exit_Command_Click

End Sub



I am trying to be able to search by Product and counterparty.
Any help is greatly appreciated, thanks!