Setting Global Variable For multi resolution values

Hello,
i would like to setup a Global variable in my AppDelegate
so i can set the speed for each resolutions.
i have already setup my appdelegate with different resources… but i need a variable to be called on my scene, so i can setup the speed of the game

Do you mean int SpeedFactor = Director::getInstance()->getVisibleSize().width

i tried the speedfactor, doesnt seems to work out for my game…
so i want to do some thing like this

if (CC_LARGE_RES)
speed = what ?
endif

I think it’s not a good idea to assiciate game logic(speed) with device feature(resolution). Consider this article http://www.cocos2d-x.org/wiki/Multi_resolution_support