Cant connect iphone to itunes?

my little brother and my sister both have their iPod touches connected to iTunes and it says their iPod and their names on the left side on iTunes. they said that when they plugged their iPod's in the computer recognized them immediately. but when i plug my iPhone into the computer a window pops up and says what system i would like to use for my iPhone camera. we all use the same account. and i just bought the movie battle los angeles it hasn't downloaded yet and you can only see it in movies and downloads. how can i get itunes to read my iphone and get that movie on my iphone? please help! thanks!