push back wont start or work on fsx help ctrl and p nothing

hi i have been getting my way around fsx i have sp2 installed and plenty add on i can't get push back to work i have added files to panel as i was told too for ground handling i press ctrl and p and nothing happens can anyone tell me if i need to download anything are what do i do to get this to work and push me back from gate basically i have fsx and accelleration installed on my high spec pc i have all airbus planes and quite a few boeing all my setting in fsx are set high my airport vehicles are set to low as well as road and sea traffic i have also vfr seenery of all uk installed and traffic 360 please help thanks again