My Iphone wont turn on ?

My Iphone one day just turned off, so i tried to turn it back on , it wont turn on, so i plug it into my computer then it turns on, and i see the apple logo for like 1min and then it goes black and turns of again, evry time i try to turn it on with my computer i see the apple logo for 1 min and then it turns of.and if its not plugged to my computer it wont react at al.....

can any one please help me ??