Combo Box / List box help

[BENatUSGS]

So I am trying to create a drop down menu in my spread sheet that doesn't require a rowsource. I need the drop down menu to be able to supply the user with a few options A B C D ect.... when they select one of the options I would like my script for the selection to place a value in a specific cell. So, "A" would return 1 "B" would return 2 and so on. Can anyone help me with this?
Thanks
Ben

[Bob Phillips]

Just use Data Validation list.