function bians(id){ for (var l=0;l<3 ;l++) { var e="document.getElementById("d"+l);" var f="document.getElementById("ss"+l);" if (l="=id)" { e.style.display="" ; f.classname="'backgroupnd_middle';" } else { e.style.display="none" ; f.classname="'backgroupnd_middle_current';" } }}