Dd_ok

Please help, I try to use DD_OK but it says it's not declared. I tried to use DxVBLib.DD_OK but it's not in there. How do I use this? I'm using DirectX7 and really need help. Here's the context of it.

VB Code:

Function ExModeActive() As Boolean
        Dim TestCoopRes As Long
        TestCoopRes = dd.TestCooperativeLevel
        If (TestCoopRes = DD_OK) Then
 
        End If
    End Function

What's 'DD_OK' ? and did you add reference of DirectX to your proj ?