How to change cell data from a dropdown list in another cell

I have a cell that has a drop down list. Once I make a selection in the cell I want to change data to another value based of the drop down list value.

(Deleted!)

first select the cell you want to edit,

and click menu “Data > Validity”.

next select “list” on the Allow Tab.

The request was from 2015-06-22. If the questioner actually comes back to read this answer, he (f/m) should also read:
Sorry! Your subject is telling me you want action on a different cell. The content of your post seems to aim at action on the same cell. The cell I am referring to using “different” / “same” is the one for which the ‘Data’ > ‘Validity’ feature is used.Please clarify.