iPhone 4 - 16GB - Used - Slight Damage .

I am selling a black iPhone 4 with a slightly water damaged screen. The phone is 100% functional and you can only tell the screen is damaged by some small "splodges" that appear under the glass, its really only noticeable when the screen is on a white background. The damage happened when the phone was lying on a table and someone spilt a drink at the other end of the table and the water ran under the phone. The functionality of the phone is absolutely fine and it is not affected in any other way. I had the phone on an O2 contract which has ended so not sure if it is locked to O2 or not. Most people just think the effect on the screen is some sort of screen saver or theme.