How to modify flash so it pulls php url every 15 seconds

[DavidPlus]

Hi flash folks. could any one tell me how to modify flash .fla file so it pulls a .php url every 15 seconds without need to refrsh to the whole page tha contains the flash. Here is how the flash is placed in page:

<object type="application/x-shockwave-flash" data="./imagerotator.swf" height="180" width="448">
  <param name="movie" value="./imagerotator.swf" />
  <param name="allownetworking" value="internal" />
  <param name="allowScriptAccess" value="never" />
  <param name="enableJSURL" value="false" />
  <param name="enableHREF" value="false" />
  <param name="saveEmbedTags" value="true" />
  <param name="bgcolor" value="#FFFFFF" />
[b]  <param name="flashvars" value="file=externalfeed.php&autostart=true&transition=fade&shownavigation=false&rotatetime:4&shuffle=true" />[/b]
  <param name="wmode" value="transparent" />
</object>
</div>