thanks a lot for your good advices guys. When I calm down and think more about my game, I totally agree with one of the above guys. That play with a "pusher" is not that bad. it will improve my ground strokes and volley, overhead and all the other skills in Tennis. Since they never go for winner. so I can try all the things I want. actually it is more like a play with myself. as long as I didn't do anything stupid, didn't make any errors. it will win sooner or later. so now, I am really looking forward to playing with that guy who beat me or the other pushers. the only reason that I can't beat a "pusher" is that I am not that good physically(not very consistently) and mentally(not patient), so I get mad and start to do something stupid.