how to change url in browser url box?
<p>I really wonder why facebook and google can change the url without reloading the page? they just change the block or content in their site.</p>

<p>I notice that when I am using facebook, when click on the "new feed" the url is "http://www.facebook.com/" and the page didn't reload, then i click on "messages" the url changed to "http://www.facebook.com/messages/" and the page still not reload just change the "content" block of the site.</p>

<p>So how do I change url without reloading the page?</p>

<p><b>edit:</b> i got the answer.<br/>
there are 2 cases here:</p>

<ul>
<li>browser support html5 (Firefox 3.6 + etc.): using html5 history. (example: www.facebook.com => www.facebook.com/messages )</li>
<li>browser dosn't support html5 (IE6, IE7, IE8 etc.): using hash tag (#) (example: www.facebook.com => www.facebook.com/#!/messages )</li>
</ul>

<p>hope this help to who have doubt like me.</p>
