HELP with Infrared emitter + sensor problems

Please do not forget to look at my previous post as well as this one....

but one more dumb question... If the IR receiver reads a 0, does that mean it is reading no infrared light or it is reading the max it can handle? Because When I ran this code... It read zeros when my light was on, and really high numbers when the light was off(almost in complete darkness), so that must mean a higher number means a lower amount of infrared being read right??

const int IRInput = A0;
void setup()
{
Serial.begin(9600);
}
void loop()
{
int onVal = analogRead(A0);
Serial.println(onVal);
}