Kenmore Fridge Freezer Not Freezing?

I have a Kenmore fridge model# 461.90032. As the title of my question states, the freezer portion of the fridge is not freezing. It is cool, but not freezing. I was thinking that it might be low on freon. If someone can give me some insight that would be greatly appreciated!

Thanks.

By Roshni from London, ONT