Gameshark 2 V1.3 help

I have a gameshark 2 v1.3 it has Need for speed most wanted codes on it but they dont work. My need for speed most wanted game for ps2 Was part of a box set that came with need for speed underground, need for speed underground2, and need for speed most want can any one tell me how to get the cheat codes to work or have other ones for me to try. ive tryed some others but when i have to in put 2 or more codes for the cheats. it wont let me. please sum one help im goin *bleep* nuts. im stuck on black list number 3 and cant get my milestones completed its hard to complete them.