The Top and bottom LCDs are interchangeable. You can buy them here: http://store.videogamecentral.com/dslcdscreen.html
or search ebay.
You will need a tri wing screwdriver to open the DS tho. You can find it online at PlayAsia.
try looking at ebay for some as is DS
shouldnt be more than 10 american, sorry for bad punctuation or spelling im not in a confortable typing position.