This way
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title></title>
<style type="text/css">
body
{
font-family: Arial;
font-size: 10pt;
}
table
{
border: 1px solid #ccc;
}
table th
{
background-color: #F7F7F7;
color: #333;
font-weight: bold;
}
table th, table td
{
padding: 5px;
border-color: #ccc;
}
</style>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<script type="text/javascript">
$(function () {
$("input[type=text], select, textarea").bind("keyup, change", function () {
$(this).attr("rel", "edited");
});
$(window).on('beforeunload', function () {
if ($("[rel='edited']").length > 0) {
return "There are some unsaved changes on the page. Do you still want to leave the page?";
}
});
});
</script>
</head>
<body>
<form id="form1">
<table border="0" cellpadding="0" cellspacing="0">
<tr>
<td>
Name:
</td>
<td>
<input type="text" id="txtName" />
</td>
</tr>
<tr>
<td>
Address:
</td>
<td>
<textarea id="txtAddress" rows="3" cols="10"></textarea>
</td>
</tr>
<tr>
<td>
Gender:
</td>
<td>
<select>
<option value="">Please select</option>
<option value="M">Male</option>
<option value="F">Female</option>
</select>
</td>
</tr>
<tr>
<td>
</td>
<td>
<input type="submit" id="btnSubmit" value="Submit" />
<a href = "Default.htm">Cancel</a>
</td>
</tr>
</table>
</form>
</body>
</html>
Demo