hi.
simple maybe. depends. but to answer the simplistic reguest....
Private Sub ComboBox1_Change()
If ComboBox1.Value = "something" Then
otherform.Show
End If
End Sub
Select case lcase(me.combobox1.value)
case is = "value1" : userform1.show
case is = "value2" : userform2.show
case is = "value3" : userform3.show
end select