Tryit Editor v1.8

Source Code:

<!DOCTYPE html>
<html>
<head>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js">
</script>
<script>
$(document).ready(function(){
  personObj=new Object();
  personObj.firstname="John";
  personObj.lastname="Doe";
  personObj.age=50;
  personObj.eyecolor="blue"; 
  $("button").click(function(){
    $("div").text($.param(personObj));
  });
});
</script>
</head>
<body>

<button>Serialize object</button>
<div></div>

</body>
</html>

Result:

W3Schools.com - Try it yourself

Edit the code above and click "Submit Code" to see the result.