function mshow(n) {
            //alert(n);
            var mybt = new Array("zd", "cs", "ms", "xfz","mth");
            for (var i = 0; i < mybt.length; i++) {
                 //alert(mybt[i]);
                if (n==mybt[i]) {
                    //alert(mybt[i]);
                    document.getElementById(mybt[i]).className = "mc";
                }
                else {
                    document.getElementById(mybt[i]).className = "mnc";
                }
            }           
        }