function alternate(objID) {
	if (document.getElementsByTagName) {  
    	var table = document.getElementById(objID);  
   		var rows = table.getElementsByTagName("tr");  
   		for (i = 0; i < rows.length; i++) {          
 			// "zebra effect", alternates classnames
     		if (rows[i].className != 'header') {
     			// any even number will be evenly divisible by 2, hence no remainder every other row
     			if (i % 2 == 0) {
        			rows[i].className = "even";
     			} else {
            		rows[i].className = "odd";
     			}      
   			}
 		}
	}
}