the answer: the man turns on one switch for around 5 minutes, then he turns the same switch off and clicks another switch on, after that he enters directly to the room, if the light bulb is on, then the last switch he used is the correct one, if not, he touches the light bulb and check if its hot, if so, then it is the switch that he used first ( the one that he turnd on and waited 5 minutes), finally, if none of the above was true, then the remaining switch is the correct one... 
