How To REMOVE SCRATCHES on GLASS – Thanks.?

I have a large scratch on my window in my room, and I have no clue how it got there. What can I do to get it removed?

I also have a scratch on my MP3 player screen. I think its glass. [ idk, you tell me ]. What can I do to get rid of it?

Is there ANYTHING I can buy to remove glass scratches?
Where can I buy it? [ I cant and will not buy online ]
How much does this product cost?