The answer was here
http://forums.macrumors.com/showthread.php?t=1163253
"I've found the following model codes for MBA 11" screens:
2010 model
LP116WH4-TPA1 (LG Phillips)
AUO B116XW05 (AU Optronics)
2011 model
LP116WH4-TJA3 (LG Phillips)
AUO B116XW05 V0, v1, v6 (AU Optronics)
LTH116AT01A04 (Samsung)
I don't know if 2011 and 2010 model screens are interchangeable, but you could change them within the same model year, so a LP116WH4-TPA1 would work with a B116XW05."