Okay I am sure it is easy to do this but I can't figure it out.

I made a movie of my kids and when I put it into itunes so I can watch it in frontrow there is a space called description but I cannot enter anything into it. The movies I bought from the Itunes store have information in there so does that mean that you can only have information in there if it is a purchased movie?

I want to enter information into it so that when it displays in Frontrow people can read about it before watching it.

Can somebody help me out please?

Thank-you in advance.