White line across laptop screen

I am fedup with Dell I have talked to them using the live support chat 4 or 5 times and they won't tell me how to fix my problem. I have a 1 pixel high white line across the bottom of my screen. I think this is a hardware problem but I don't know if it is the screen or the graphics card. I am running Dell intel Core 2 Duo E1505 with windows vista. How do I tell what I need to fix it and where can I get the parts for cheap?