Private Sub ComboBox1_Exit(ByVal c As MSForms.ReturnBoolean)
If ComboBox1 = "" Then c = True
End Sub
Private Sub ComboBox1_Change()
If ComboBox1 = "" Then Application.OnTime 1, "show": Unload Me
End Sub
Private Sub UserForm_Initialize()
ComboBox1.List = Array(1, 2, 3)
ComboBox2.List = Array("aaa", "bbb", "ccc")
ComboBox3.List = Array(111, 222, 333)
End Sub