Photoshop Problem: Rotating Text 90 Degrees Clockwise, How Do I Do It?

I’m doing a DVD cover design for a class project, and I would like to put the name of the movie on the spine of the DVD case, but not so the letters are up and down, so the letters still go from left to right but turned 90degrees to the right. I’ve typed out the text, selected it (in the correct layer) and right clicked to transform selection, so that I can rotate it, but it doesn’t let me. How do I do this?