//ul的切换效果 第一个参数：ul的id，第二个参数：ul中li的id，第三个参数：切换前的样式，第四个参数：切换后的选中样式
function selnav(ulid, selfobj, oldclass, newclass, divid, sel, length) {
      /*  try {*/
            var tag = document.getelementbyid(ulid).getelementsbytagname("li");
            var taglength = tag.length;
            for (i = 0; i < taglength; i++) {
                tag[i].classname = oldclass;
            }

            selfobj.classname = newclass;

		if(divid!=""){
            for (i = 1; i < length + 1; i++) {
                document.getelementbyid(divid + i).style.display = "none";
            }
            document.getelementbyid(divid + sel).style.display = "block";
		}
        /*} catch (e) {
        }*/
}