how to append dropdown list selected value to formview column string value during Updates and inserts?

hi,
I have Formview bound to objectdatasource with Insert, and Edit templates wired up.
One of columns in the database is  "Mobile Number"
Next to the textbox Mobile -  I have a dropdown list with Country Dialing codes

what I want to do is append the Selected Value of DDL to the TextBox  "Mobile" during
edits and Inserts.   This is done updating and inserting events

Code below
    <p>           Dialing Country code           </p>                                                   & ...