ÔÚ Combo1µÄ ClickÊÂ ¼þ ÖÐ Ìî ³ä Combo2£¬ Èç £º 
    Dim nIndex As Integer 
    Private Sub Combo1_Click() 
     If nIndex = Combo1.ListIndex Then Exit Sub 
     nIndex = Combo1.ListIndex 
     Combo2.Clear 
     Select Combo1.ListIndex 
     Case 1 
     Combo1.AddItem "A-A" 
     Combo1.AddItem "A-B" 
     Case 2 
     Combo1.AddItem "B-A" 
     Combo1.AddItem "B-B" 
     End Select 
    End Sub 
     
    Private Sub Form_Load 
     nIndex = -1 
    End Sub 
<END>    