function odd_rows()
 	{
	 var rows = document.getElementsByTagName('tr');
	 var k = 0;
	 for (var i in rows)
		 if(!rows[i].getAttribute('class'))
		 	{
	 	 	 if(k++%2)
				rows[i].setAttribute('class', 'odd');
			}
		 else
		 	k = 0;
	}

 window.onload = function()  
        {
	 odd_rows();
	}