javascript - Jquery Type error : id is null

Question

This is the script i m using but it is giving me error Type Error: x is null.

 <script type="text/javascript"> 
    var $j = jQuery.noConflict();
    $j(function()
    {
      if (entityId != null && entityId != "")
      {
        var x=document.getElementById("my_act");
        alert(x.innerHTML);
      }
    });
</script>

Answer 1

There is no element with an ID of my_act on the page when this script is run.

Also, if you are using jQuery why not actually use jQuery and do $("#my_act") instead of document.getElementById("my_act")