Please access this Photoshop tutorial before you ask me a question. This tutorial will have many answers and you can learn to trouble shoot on your own. I will be happy to help, but only if you have checked the tutorial first for the answer.
I do this because there are many of you and only one of me, so needless to say it makes it difficult to get to everyone when they need me and I want to make sure and help you optimize your computer lab time.