Movie as backround doesnt move

Hi ,

i#ve made an animation , and in the backround is a movie ( a area uand i animated a bullet , so the bullet fly in the are ) but when i set all the keyframes and so on , the movie goes 10 sec long . But my movie doesnt movie , when i render i see all the time the same frame , the first . I think i have to to set the last and the first frame of the movie but i dont know where i have to make that . or i have forgotten to make a other thing .

Plz help me thx