Mr Coops

Samples Assigned To A Midi Keyboard?

Hi,
Firstly I apologise if this is elsewhere I did perform searches but couldn't find anything, maybe I'm being stoopid wouldn't be the first time.
Basically what I'm after is a piece of software that would let me assign samples which would them be activated via my yamaha keyboard. So each key on the Yamaha keyboard would be a different sample. Hope this makes sense.
A little background may help, I'm a DJ (lol) using vinyl and a standard mixer, I can wire my mac up to the mixer so that I can mix MP£'s or whatever that way, however what I'm trying to do is set it up so I can trigger a sample say -
'I want it smooth and by the numbers' via my keyboard. I would have different samples assigned to different notes on my keyboard so wouldn't have to go back to my Mac to change the sample I could use.

any suggestions, any response much appreciated.

Cheers
Coops