window.onload = function () { 
colorRowsTR(); 
colorRowsLI(); 
function colorRowsTR() {
       var myTR = document.getElementsByTagName('tr');
       for (var i=0;i<myTR.length;i++) {
               if (i%2) {
                       myTR[i].className += ' on';
               }
       }
}
function colorRowsLI() {
       var myLI = document.getElementsByTagName('li');
       for (var i=0;i<myLI.length;i++) {
               if (i%2) {
                       myLI[i].className += ' on';
               }
      }
}
}