[c-nsp] Cisco asa5550 url filter

[Bunny Singh]

Hi, 
 
I am looking to do the url filtering on my cisco 3660 router. 
 
Actually i want to block some of the youtube url for being access from my clients. I have checked through match protocol http and stuff from google but i didnt got any success.  
 
So is it any way to filter url's and highly appreciate if somebody can share the examples also.
 
ios version:--12.3 (12) release software (fc3)
 
Regards
Bunny