title: Dynamically Changing Value in APEX Based on Select List Selection
body: <p>I currently have a select list with the values: 1, 2, 3, 4 &amp; 5. These correspond to a column in table "DVD" called "DVDID", and these are the only values in this column in the table.</p>
  
  <p>In the table "DVDCOPY" records exist containing the all DVDIDs (1,2,3,4,5) with a different DVDCOPYID.</p>
  
  <p>E.g. a record from the DVDCOPY table is:</p>
  
  <pre><code>DVDCOPYID DVDID DISCCONDID
  1         1     1
  </code></pre>
  
  <p>My question is, how can I make it so that once a DVDID is selected from the select list, the DVDCOPYID changes dynamically based on this selection? E.g. once 1 is selected in the DVDID select list, the value for DVDCOPYID also changes to 1 automatically.</p>
  
  <p>My form currently looks like this, if this helps:
  <a href="http://i.stack.imgur.com/SsAqC.jpg" rel="nofollow">APEX Form</a></p>