[jQuery] img src problem in IE6

$('#fp_menu a').each(function()
 {
        dev_id = querySt("dev_id");
        $(this).click(function()
        {
                new_src = "http://"+this_domain+"/development/images/"+dev_id+"/
floorplan/"+this.id;
                $('#fp_img').attr({ src: new_src });
        });

});

in IE6 src is not changing.its work well in firefox and IE7