I have used the following code which works great, the only thing is that I
want my subform to open as a dialog form.

Private Sub Inactivate_Click()
' This code created in part by Command Button Wizard.
On Error GoTo Err_Inactivate_Click

   Dim strMsg As String, strTitle As String
   Dim intStyle As Integer
   Dim strDocName As String, strLinkCriteria As String

   ' If CompanyName control is blank, display a message.
   If IsNull(Me![Company_Name]) Then
       strMsg = "Move to the vendor record you want to see, then press the
Inactivate button again."
       intStyle = vbOKOnly
       strTitle = "Select a Vendor"
       MsgBox strMsg, intStyle, strTitle
       Me![Company_Name].SetFocus
   Else
   ' Otherwise, open Inactivate Vendor form for current vendor.
       strDocName = "POP:Company_Inactivation"
       strLinkCriteria = "Company_ID = " +
CStr(Forms![F:Vendor_Entry]![Company_ID])
       
       DoCmd.OpenForm strDocName
             
       Forms![POP:Company_Inactivation].Filter = strLinkCriteria
       Forms![POP:Company_Inactivation].FilterOn = True
                       
   End If
             
Exit_Inactivate_Click:
   Exit Sub
   
Err_Inactivate_Click:
   MsgBox Err.Description
   Resume Exit_Inactivate_Click
       
End Sub

If I use DoCmd.OpenForm strDocName, acNormal, ,
Forms![POP:Company_Inactivation].Filter = strLinkCriteria, acFormEdit,
acDialog
the form comes up in dialog mode but the filter is not applied.  I am
stumped! Any suggestions would be appreciated.

Thanks!