window.onload = init;

function init() {

     alternate("theTable");

}


function alternate(id) { 

     if (document.getElementsByTagName) {  

          var table = document.getElementById(id);   

          var rows = table.getElementsByTagName("tr");   

          for(i = 0; i < rows.length; i++) {           
 
               if(i % 2 == 0){ 

                    rows[i].className = "even"; 

               } else { 

                    rows[i].className = "odd"; 

               }       
         } 
    } 
}