Not Smooth Jquery Slide Down Menu -

i'm trying add drop down menu site when below size menu fits screen(like else). it's been going fine until now, i'm virtually done slide effect not smooth.

here site: http://www.divisionforty.com/wallspace/ resize page , menu change.

here code i'm using:

jquery:

<script>     $(function() {         var pull        = $('#pull');                 menu        = $('nav ul');          $(pull).on('click', function(e) {             e.preventdefault();             menu.slidetoggle("fast");         });          $(window).resize(function(){             var w = $(this).width();              if(w > 900 && menu.is(':hidden')) {                 menu.removeattr('style');             }         });          $('li').on('click', function(e) {                            var w = $(window).width();             if(w < 900 ) {                 menu.slidetoggle("fast");             }         });       });      </script> 

css:

 @media screen , (max-width: 900px) {    #pull{             right:10px;             display:  block;             position: absolute;             width:50px;             background-image: url("../img/nav_icon.png") no-repeat;  }     #nav{             display:none;             position: absolute;             padding-top:0;      }      #nav li {         width: 100%;         float: left;         position: relative;         border-bottom: 1px solid #262626;       }       #nav {           text-align: left;           width: 100%;           text-indent: 25px;             background: #ffffff;                 }             #nav a:hover {           color:#afafaf;       }   }   

that believe required. can me sorted!

denver

set height #nav.

#nav { height: 100% }