run javascript code on AJAX request

i have a upload dialog that allow me to upload files with plupload, but i have a problem,
when i load content directly, it work, but when i load it with an ajax request, javascript code will execute, but dom elements not ready yet, when i make a small delay with timeout, it worked, how i can run javascript code , after ajax dom ready?

blew code load with ajax request:

    <form enctype="multipart/form-data" method="POST" action="admin.php?do=media&action=file-upload">
 
     <div id="uploadForm">
 
         <div id="fileList">
 
 
 
         </div>
 
         <a href="#" id="selectFile">[Select File]</a>
         <a href="#" id="uploadFile">[Start Upload]</a>
 
     </div>
 
 </form>
 
 <script type="text/javascript">
     // $(function(){}); not working when data loaded with ajax request
         var ajaxUpload = new plupload.Uploader({
 
             runtimes: 'gears, html5, flash',
             url: 'upload.php',
             browse_button: 'selectFile',
 
         });
 
 
         ajaxUpload.bind('Init',function(param){
             console.log(param);
             console.log($('selectFile'));
         });
 
         $('#uploadFile').click(function(){
             alert('Something');
         });
 
         ajaxUpload.init();
 
 
 </script>
 

---