gameshark help/ general cheat help please

okay i bought gameshark to use on my playstation cause i have been through ffx about 4-5 times COMPLETLY and was fed up of doing blitzball and suchlike, unfotunatly my gameshark wont work it just come us saying please enter a playstation2 disc, whats going on? is it because im in england and gameshark is only for USA or summing?
which is what im betting on.....arrrgggh"!
if this is the case i would like to know lease seeing as im in the uk what other UK playstation2 users use for cheats on their consoles? where can i get these things ? how much?
thankyou

I assume you got the PS2 compatible Gameshark, yes? It may not be working because it's not encoded to the right region. It should have the region on the packaging, check and see if it says PAL.

Gameshark can just be a jerk on systems anyway, even if it is compatible. Does it make noise when it goes in? Like a... really strange, painful sounding noise?

If it isnt the region that's the problem, you can try a little trick that sometimes works for me.
1. Insert a PS2 game. Doesnt matter which.
2. Wait till it gets to the title screen or thereabouts, then eject the game DO NOT RESET.
3. Insert the Gameshark disc and then reset.

Sometimes that will work.