function oracalizeReading(uint256 _reading) {
			if(msg.value<requiredGas) {  
				if(freeReadings[msg.sender]==0) throw;
				freeReadings[msg.sender]--;
			} 		
			if(_reading<lastReading[msg.sender].value) throw;
			if(_reading<requestReading[msg.sender].value) throw;
			if(now<lastReading[msg.sender].timestamp+secondsBetweenReadings) throw;			
			
			requestReading[msg.sender]=Reading(now,_reading,plz[msg.sender]);
			OracleRequest(msg.sender);
			owner.send(msg.value);
		}