Last time i posted an avatar question it was "how do u get the little picture by ur name" but, uh, yeah...

m'kay, so i found a webpage, saw a picture i liked, good size (not too big) saved it as a jpg file. Used the little browse box to pick it, n clicked submit changes or whatever. It said that there was sumthing wrong w/ the file n it couldn't read it or sumthing similar...so whats wrong? It couldn't be messed up or nething, i just saved it...*is confused* sum1 help me, i want my new avatar!!!