title: Multiple DropDownList but same action
body: <p>I have two DropDownList with OnSelectedIndexChanged="SelectedIndexChanged" but I need to know in the C# code withch one is the one I used.</p>
  
  <p>How can I know that?</p>
  
  <p>Answering the questions:
   I'm using Web Forms  and I'm trying to change some GridViews Source from a choseen option in a DDL but the web had the same DDL  (with different IDs) in several places and I can't delete them...</p>