jQuery().ready(function() {
      jQuery("div:last").html(" ");

      jQuery('#top_panel_arrow').hover(function() {
            jQuery(this).css('cursor','pointer');
                }, function() {
              jQUery(this).css('cursor','auto');
      });
      
      var shown = "false"

        jQuery('#top_panel_arrow').click(function(){
              if (shown == "false"){
                jQuery("#top_panel").animate({"margin-top": "+=75px"}, "slow");
                jQuery('#top_panel_arrow').css("background-image","url(img/top_panel_arrow_up.png");
                shown = "true";
              }else{
                 jQuery("#top_panel").animate({"margin-top": "-=75px"}, "slow");
                 jQuery('#top_panel_arrow').css("background-image","url(img/top_panel_arrow_down.png)");
                shown = "false";
              }
              }); 

    });