My Code Not Working

My Code Not Working

  2. <script type='text/javascript' src='http://ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.min.js'></script>
  3. <script type="text/javascript">
  4.    
  5. for (var i =0; i>=50; i++) {
  6. var pos=($("portfolio-items").eq(i).position.top)+($("portfolio-items").eq(i).height())-($("portfolio-items").eq(i+4).position.top);
  7. $("#div").eq(i+4).css("margin-top", pos);
  8. }

  10. </script>