variable printing

HTML

<form id="myForm">Your name:
    <input type="text" id="firstname" />
    <input type="button" value="submit" id="submit" />
</form>
<div id="test">Click me to test!</div>

JavaScript

$('#submit').on('click',function(){
        var firstname = $('#firstname').val();
        alert(firstname + ' is the one who makes websites?');
    });