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";
			 }      
		}
	}
}