e.target.id returns a blank value on alert, what have i done wrong ?

1. 
   <div id="navbar">
            <ul class="top_menu" id="pula">                    
                <li id="home"><a href="#"   title="home page"><b>home</b></a></li>
                   <!--<li><a href=""   title="our software">software</a></li>
                   <li><a href=""   title="work / portfolio">work</a></li>  -->
                   <li id="contact"><a href="#"   title="Contact"><b>contact</b></a></li>
               </ul>
   </div>
   
   
   
   
   
   
   
   
2.  $(document).ready(function(){
       $(".top_menu > li").click(function(e){
           var x = e.target.id;
           alert(x + "ceva");
          //  if(e.target.id == "home"){       */
                 $('.replaceble').slideUp().load('html/main_content.html').slideDown(5000);
         //  }
            if(e.target.id == "contact"){      
                 $('.replaceble').slideUp().load('html/contact.html').slideDown(5000);
            }
       });
    });