Hello, i work for a web development company and during the one year i have spent here, there were no improvements in the technologies we used to built our websites. I introduced jquery to them (buying the Novice to Ninja by Sitepoint) and now, i want to get rid of all these crappy PHP from scratch and use a PHP framework instead.

So what reasoning i can use to convince my boss to switch, and how to convice the other developers too?