I was away to Dehradun to appear for my exam and in my absence my Samsung 940BW screen was probably rubbed with some greasy kinda cloth ( probably for cleaning ). There are suface streaks on it. Am afraid even to clean it- is it plastic ? is there a solution for cleaning & what kinda cloth to use for cleaning ?- somebody suggested Isopropyl alchohol plus water- plz. guys somebody would have real experience in this !