"I have LCD 16 pin (18 characters X 2 Lines), but i do not know it's brandmark. so i'm getting confuse to determine of each pin out function. "

Understandably a hopeless situation !

Anyway one of the following can take you one step near the solution :

1. See if you are able to read the IC number that is one the backside of the module. While many manufacturers of the modules use chip-on-board ( ICs without pins which are part of the PCB - don't know what to call them )some use standard chips where you can read the numbers. Once you pick up the number hit Google with it.

2. Look for any logo on the module - then hit these sites to look for a match :

http://www.icmaster.com/LogosA-M.asp
http://www.icmaster.com/LogosN-Z.asp

3. If you can photograph the module ( front and back ) and post it here as a JPG file - someone will be able to recognize it. ( Not a very sure way this but better than keeping it useless )

Raghu