squid page manipulation

Hi,

Is that possible to manipulate a page that squid proxies?
For example, in that page, there is an javascript alert(); function and 
i want to discard that so the browser doesn't see that.
Basically, I want that squid change the HTML source codes from the pages 
that i download, with matching criterias.

Best Regards,

Carlos Silva, CSilva
Web: http://www.csilva.org/