My iphone 4 screen has a black dot in the top right corner?

Ok so my iPhone 4 has a black spot on the top right corner of the screen and i don't know what to do can somebody give me advice on what to do!

Don't freak out if you dropped it or it might of gotten wet can cause that to happen. Just wait till your next update and get another one. Just don't get it wet or drop it again or it will Permanently damage it further.