Whats wrong with my laptop screen?

i have an acer one and near the right hand corner there is a line that's maybe an inch or two and it seems to change colors depending on the site i am on.. like right now it's white but when i watch a movie it goes greenish... whats wrong with it. do i need to take it in? will it cost alot to fix it? i tried turning it on and off even rubbing it gently. also when i take a screen cap of my screen the line does not show up...