Why won't the darn tag work?????!

Argh! It's driving me crazy! C.R.A.Z.Y... CRAZY! I can't get the image tags to work. I back-tracked, I copied, I debugged, everything, I did everything and STILL my images can't be posted here. WHY? I did it before. SO WHY CAN'T IT WORK NOW? ARRRRRRRGHHHH! WHY WHY WHY? *Feet stomping, jumping up and down* I even sign up a free website and all AND still it won't work. I've recheck my spellings and typing and STILL (!) IT WON'T WORK. Somebody, please HELP ME!