Issue in Adding property to string object
<pre><code>var s = "Hi";

Date.now = function (){
    return new Date();
}

s.createdOn = function (){
    return new Date();
}

alert(s.createdOn()); // This is not working
alert(Date.now()); // This works fine
</code></pre>

<p>Am i violating any rule. Because i can add new property to Date class but not to string class. why?</p>
