motorola atrix with straight talk apn

hi i have a motorola atrix from att i switched to straight talk and brought this phone with me i cant get it to recieve mms or pic msgs everything else works can anyone help me with this problem please straight talk wont or cant help me

via Cell Phone Forums (French) http://cellphoneforums.net/fr/straight-talk/t365454-motorola-atrix-with-straight-talk-apn.html