gprs - file - computer

Hi everyone, i want to controll my arduino with internet and i've thinked at a thing like this:
the arduino check a page where i put a command that in the arduino program means something and execute it. The problem is that if i want to control a relay, i turn it on with the command "relay" and i turn it off with "relayoff" so the program search relay and it turn on the relay and than wait for reley off for turn it off but when i want to re-on the relay he find the old relayoff and don't turn it off. My application for write the file that the arduino do is in php so i wa wandering if i can program the arduino for click a button(thath in a page of php will erase the file). If not i ask you if you have some suggestion.

Bye bye and thanks for all the helps that you are giving to me

p.s. I'm italian

but when i want to re-on the relay he find the old relayoff and don't turn it off.

Finds it where? If the php script is writing to a file, isn't it erasing the old contents? How is the Arduino accessing the file on the PC that the PHP script is writing to?

You need to post some code, Italian or not.