can you see what wrong in this that i used ur own code
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Untitled Document</title>
<script language="javascript">
function calculate_total(className, div){
var elements = document.getElementsByClassName(addition_textbox);
var total = 0;
for(var i = 0; i < elements.length; ++i){
total += parseInt(elements.value);
}
document.getElementById(div).innerHTML = "Total: " + total;
}
</script>
</head>
<body>
<form name="form1" method="get">
<input type="text" name="box1" id="box1" class="addition_textbox" value="4" /><br />
<input type="text" name="box2" id="box2" class="addition_textbox" value="1" /><br />
<input type="text" name="box3" id="box3" class="addition_textbox" value="14" /><br />
<input type="text" name="box4" id="box4" class="addition_textbox" value="214" /><br />
<input type="text" name="box5" id="box5" class="addition_textbox" value="2" /><br />
<input type="text" name="box6" id="box6" class="addition_textbox" value="8" /><br />
<input type="text" name="box7" id="box7" class="addition_textbox" value="3" /><br />
<input type="text" name="box8" id="box8" class="addition_textbox" value="16" /><br /><br />
<input type="submit" name="calculate" id="calculate" value="Calculate Total" onclick="calculate_total('addition_textbox', 'total_text')" /><br />
<div id="total_text"></div>
</form>
</html>