I need help with world of warcraft?

I'm playing as a warlock and every time i log in i can i use the sword one time but when i try to use it again i cant use it the only thing that i can use without any problems are the spells.. my sword is one handed and i have another one that is auto attack and i cant use either pllzzzzz help can anybody tell me what is wrong.. i'm playing the trial for cataclysm