dropdown check list

dropdown check list

Hi All,
I am using 'defer parsing of js ' for dropdown list. But it is not working when clearing the

cache,
Here is the code:
<select name="deptT" id="deptT" multiple="multiple"  class="filterSelect" style="width:85%;">
    <option>1111</option>
    <option>2222</option>
    <option>3333</option>
    </select>
<script type="text/javascript">
 var $jj;
 function downloadJSAtOnload() {
 
 element4 = document.createElement("script");
 element4.src = "js/jquery.js";
 document.body.appendChild(element4);
 
 var elementA = document.createElement("script");
 elementA.src = "js/jquery-1.6.1.min.js";
 document.body.appendChild(elementA);
 
 var elementB = document.createElement("script");
 elementB.src = "js/jquery-ui-1.8.13.custom.min.js";
 document.body.appendChild(elementB);
 
 var elementC = document.createElement("script");
 elementC.src = "<?=$cz_path.""?>js/ui.dropdownchecklist-1.4-min.js";
 //elementC.src = "js/ui.dropdownchecklist.js";
 document.body.appendChild(elementC);
 
 elementC.onload = function(){
     $jj = jQuery.noConflict(true);
     call();
 };

 
 }
 
  // Check for browser support of event handling capability
 if (window.addEventListener)
 window.addEventListener("load", downloadJSAtOnload, false);
 else if (window.attachEvent)
 window.attachEvent("onload", downloadJSAtOnload);
 else window.onload = downloadJSAtOnload;
 
 function call(){
  
   $jj("#deptT").find('option:first').attr('selected','selected');
   $jj("#deptT").dropdownchecklist("refresh");
 
   $jj("#deptT").dropdownchecklist( { firstItemChecksAll: true, width: 100 ,
                onComplete: function(selector) {
                    var values = "";
                    for( i=0; i < selector.options.length; i++ ) {
                        if (selector.options[i].selected && (selector.options[i].value != ""))

{
                            if ( values != "" ) values += ";";
                            values += selector.options[i].value;
                        }
                    }
                  
                }
              
            });
 }
 </script>

 
But loading the js in normal way it is working fine:
Here is the code:
<select name="deptT" id="deptT" multiple="multiple"  class="filterSelect" style="width:85%;">
    <option>1111</option>
    <option>2222</option>
    <option>3333</option>
    </select>

<script type="text/javascript" src="js/jquery-1.6.1.min.js"></script>
<script type="text/javascript" src="js/jquery-ui-1.8.13.custom.min.js"></script>
<script type="text/javascript" src="js/ui.dropdownchecklist-1.4-min.js"></script>

<script type="text/javascript">
  var $jj;
 
  function call(){
  
   $jj("#deptT").find('option:first').attr('selected','selected');
   $jj("#deptT").dropdownchecklist("refresh");
 
   $jj("#deptT").dropdownchecklist( { firstItemChecksAll: true, width: 100 ,
                onComplete: function(selector) {
                    var values = "";
                    for( i=0; i < selector.options.length; i++ ) {
                        if (selector.options[i].selected && (selector.options[i].value != ""))

{
                            if ( values != "" ) values += ";";
                            values += selector.options[i].value;
                        }
                    }
                  
                }
              
            });
 }
 
 
 $jj = jQuery.noConflict();
 call();
 </script>

I need to use defer parsing of js.
Please help me what is the problem. And what i need to do for defer parsing of js.
Please help me asap.

Thanks in advance ...