<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title></title>
<meta charset="utf-8" />
<script src="js/jquery-1.8.3.js"></script>
<script type="text/javascript">
$(function () {
$('#btn1').click(function () {
var num1 = $('#txt1').val();
var num2 = $('#txt2').val();
var num3=parseInt(num1) + parseInt(num2);
$('#txt3').val(num3);
});
});
</script>
</head>
<body>
<input id="txt1" />+<input id="txt2" /><input type="button" value="=" id="btn1" /><input id="txt3" />
</body>
</html>