Reversing the analogue input.

Projects Programming
5 
void loop()
{ 
potentioValue = analogRead(0);
potentioValue = map(potentioValue, 0,1023,255,0);
analogWrite(9, potentioValue);
}

or

void loop()
{ 
potentioValue = analogRead(0);
potentioValue = 1023 - potentioValue
potentioValue = map(potentioValue, 0,1023,0,255);
analogWrite(9, potentioValue);
}

?