function alternate(id){
 if(document.getElementsByTagName){  
   //var table = document.getElementById(id);
   //var table = document.getElementsByTagName(id);  
   var rows = document.getElementsByTagName("tr");  
   for(i = 0; i < rows.length; i++){          
 //manipulate rows
     if(i % 2 == 0){
       rows[i].className = "licha";
     }else{
       rows[i].className = "suda";
     }      
   }
 }
}
if(window.addEventListener) {
  window.addEventListener("load",function() { alternate("table"); },false);
}
else if(window.attachEvent) {
  window.attachEvent("onload",function() { alternate("table"); });
}
else {
  window.onload=function() { alternate("table"); };
}