Which guitar?

Go to a local pawn shop or second hand store. Purchase a medium priced guitar. If you don't stick with it, then you won't lose too much! Just make sure the neck is straight or take someone with you who knows a little bit about guitars! Almost every brand has the big names and then the cheaper versions. Just be careful.

I also have acoustic guitar. Recently i bought this guitar. Before i never play guitar. That's why i bought this guitar as this is the best guitar for the beginner. After few days i will buy one more for my younger brother.

Well, you can get an electric that is compairable in price to an acoustic. If you have your heart set on acoustic though, don't fool around with a cheap one. It will be more difficult to play and probably wind up discouraging you. So if you do get an acoustic, I highly recomend getting a good one. Ovation is probably the best make but it is pretty expensive. There are lesser brands that are still pretty good. Yamaha, for example isn't too bad for a mid priced acoustic. Play a number of them in the music store (if they dont let you try them out first, dont buy from that store), find one that is comfortable, has low action (meaning the strings are pretty close to the fret board and not hrd to press down) and just feels good in your hands.