function tableChange() 
{
var rows = window.document.getElementsByTagName('tr');
for(var i = 0; i < rows.length; i++)
{
var trObj = rows.item(i);
if(i%2==0) {
trObj.style.backgroundColor = "#fff";
}
else { 
trObj.style.backgroundColor = "#f5f5f5";
} 
}
}