Cropping and resizing in PSP9

I was trying to make an icon the other day, and I cropped the picture to the area that I wanted. However, I had to unlock the aspect ratio to get the size to 100x100 pixels. When I did that, the picture went out of proportion. How do I keep the original dimensions but still keep it to 100x100? I tried looking in the archives, but I didn't find anything that could answer my question.

Help!