Checkout the complete HTML, Copy and save it in HTML extension.
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.0/jquery.min.js"></script>
<script type="text/javascript">
$( document ).ready(function() {
$('select[name=country]').on("change", function(e){
if($(this).val() == 'USA'){
alert($(this).val());
window.location.assign("http://www.w3schools.com")
}
//window.location.url="www.google.com";
});
});
</script>
</head>
<body>
<Select name="country">
<option value="India">India</option>
<option value="USA">USA</option>
</Select>
</body>
</html>
Hope this helps.