<!DOCTYPE html>
<html>
<head>
<script src="/lib/jquery-1.12.2.min.js"></script>
<script>
$(document).ready(function(){
$("button").click(function(){
alert($("input:text").val());
});
});
</script>
</head>
<body>
Firstname: <input type="text" name="fname" value="Peter"><br>
Lastname: <input type="text" name="lname" value="Griffin"><br><br>
<button>Return the value of the first input field</button>
</body>
</html>