title: Populating options for drop down list
body: <p>I have a list that I will have users enter data into, each user needs to select their own location.  First I created a drop down field with all the options.  The column can be set to force unique values, but this doesnt check until the end when the user goes to save.  </p>
  
  <p>Is there a way to check if the users selection is already entered, immediately when the option is selected?  (without having to hit save)</p>
  
  <p>OR </p>
  
  <p>Another option I tried was:</p>
  
  <ol>
  <li>Create a separate list with two columns: <code>name</code> and <code>saved</code>.  Call it <code>Location_List</code></li>
  <li>Create a view that displays all where <code>saved = no</code> on <code>Location_list</code></li>
  <li>Populate the options on the <code>mainList</code> from a look up the the <code>Location_List</code>. This works.</li>
  <li>Add a workflow action to <code>mainList</code> that updates <code>saved = yes</code> on the <code>Location_List</code>. This part doesn't work.  Does sharepoint allow this though?</li>
  </ol>
  
  <p>Is there an easier way to accomplish this?</p>