[RESOLVED] when i drop down combo box and select any one how to transfer releated text in txtbox

Hi All,

I have one Combo box with the list of All State name of India. my problem is that when i select a State name then text box show me a code of that particular state. like if i select a State "Andaman and Nicobar Island" from combo box then if show "1" in other Text box.

I do code in Combo box Drop Down property but it is not working. it is like...........
Private Sub Combobox1_Dropdown()
if Trim$(Combobox1.Text) = "Andaman and Nicobar Island" Then
txtbox1.Text = "1"
End If
End Sub

Above mention is my code please give me your code if you have any shorter code then please tell me because i have 36 number of State and all the state has different code so if there is any shorter way to coding this then it is ok.......... Please Help me ................. Thank you very much for Reading my problem and giving solution.