after repaired front assembly volume doesn't work

I recently fixed a cracked screen on an iphone 3GS 8gb and the touch screen works fine the only 2 issues im having is that one is the volume doesn't work - not sure if it is because of repair or if it was like that I shoulve charged and checked - but anyway also, the vibrator switch is like loose I think. With the slightest touch it spasms between vibrating on and off and on and off again...How do I fix!? thanks!