How to get the handle of child window (from MDI) using VB6?

Dim lngHWnd As Long

    lngHWnd = FindWindowEx(Form1.hWnd, 0, vbNullString, vbNullString)

    Do Until lngHWnd = 0
        Debug.Print lngHWnd
        lngHWnd = FindWindowEx(Form1.hWnd, lngHWnd, vbNullString, vbNullString)
    Loop