Stop duplication in a combo box

hi,
below is my code which i have for a drop down list within my userform...
i have been asked to select a name from a listbox then use the combo box to select a "mr" "miss" etc to them show up together in a label.

the problem i have is that every time i click on the drop down it duplicates the list that is already there,,
could someone please advise of a way to stop this

thank you

Private Sub comList_DropButtonClick()
With comList
    comList.AddItem "Miss"
    comList.AddItem "Mrs"
    comList.AddItem "Mr"
    comList.AddItem "The Awesome"
    comList.AddItem "Doctor"
    comList.AddItem "The Incredible"
End With
End Sub