need help

ok i play this game i just need help

basically its a script for when im afk, so if any dynamite drops, i move out of the way

what im stuck at, is how can i use the MoveBackward(1); for 3 seconds, then make it stop

here is the script, thanks

function enemychecker()
{
cancel($enemychecker);
$enemyfix = 0;
%me = ServerConnection.getControlObject();
$enemy = findDTS("dynamitedrop.dts", %me, 20.0, 1, 0, 1);
if(IsObject($enemy))
{
  %enemy = $enemy.getTransform();
  $playerpos = ServerConnection.getControlObject().getTransform();
  $enemydist = vectorDist($playerpos, %enemy);
  moveBackward(1);
%mymsg = "1..";
 say(0,%mymsg); 
 return;
}
$enemychecker = schedule(500,0,"enemychecker","");
}

moveMap.bindCmd(keyboard,"ctrl m","","enemychecker();");
moveMap.bindCmd(keyboard,"alt m","","cancelenemychecker();");