iRules for reverse proxy

Hello, First, I'm sorry for my english ; I'm french and I talk a very bad english... I'm new with BigIP and with iRules, so I have some difficulties to do what I want... :-( I have a BigIP 6900, and I try to use it like a load balancer (normal!) but like a reverse proxy too... I have understand that I must use iRules, but I would like to know what iRules I must use to select the http requests which are good (no errors, crc ok, ...) ? I have read the wiki of iRules, but I don't find a solution... Thank you in adavance for your help!