Web Site Suddenly Stops Responding

[CrusaderAD]

I have a website which I can browse, no problem. After a while, it just stops responding and I have to restart my browser in order to get back onto it. Other sites come up fine, even while my site is "loading", and this happens in multiple browsers. So I know it's got to be the site iteself. Any ideas for a cause?

[athampan]

Are there any errors in the server logs (what server is it running, lighttpd or apache2 or nginx)? Also, you could use firebug to check whether there are any javascript errors.