thanks a million, the cause of the problem was bugging me every day. I can't stop thinking about it. LOL
U helped me overcome this problem.
I roughly know it was the ArrayIndexOutOfBoundsException: -1 giving problem, but i didn't know -1 was a illegal state in java ArrayIndexOutOfBoundsException: -1, thus unable to overcome it myself. ;D I was trying many ways but just can't solve it alone.