noob: project 04 from A. P. Book code error

Hi,
I'm doing the 4th exercise on the Arduino (Genuino) project book, I copied and understood the code from the book, I can't compile it though, I get this error:

Arduino: 1.6.6 (Mac OS X), Board: "Arduino/Genuino Uno"

.../sketch_dec12a.ino: In function 'void loop()':
sketch_dec12a:29: error: 'redSensorPin' was not declared in this scope
redSensorValue = analogRead(redSensorPin);
^
sketch_dec12a:31: error: 'greenSensorValue' was not declared in this scope
greenSensorValue = analogRead(greenSensorPin);
^
sketch_dec12a:31: error: 'greenSensorPin' was not declared in this scope
greenSensorValue = analogRead(greenSensorPin);
^
sketch_dec12a:43: error: 'greenValue' was not declared in this scope
greenValue = greenSensorValue/4;
^
exit status 1
'redSensorPin' was not declared in this scope

This report would have more information with
"Show verbose output during compilation"
enabled in File > Preferences.

this is the code:

const int greenLEDPin = 9;
const int redLEDPin = 10;
const int blueLEDPin = 11;
const int redSendorPin = A0;
const int greensensorPin = A1;
const int blueSensorPin = A2;
int redValue = 0;
int greenvalue = 0;
int blueValue = 0;
int redSensorValue = 0;
int greensensorValue = 0;
int blueSensorValue = 0;

void setup() {

Serial.begin(9600);
pinMode(greenLEDPin, OUTPUT);
pinMode(redLEDPin, OUTPUT);
pinMode(blueLEDPin, OUTPUT);

}

void loop() {
redSensorValue = analogRead(redSensorPin);
delay(5);
greenSensorValue = analogRead(greenSensorPin);
delay(5);
blueSensorValue = analogRead(blueSensorPin);

Serial.print("Raw Sensor Values \t red: ");
Serial.print(redSensorValue);
Serial.print("\t green:");
Serial.print(greenSensorValue);
Serial.print("\t blue: ");
Serial.print(blueSensorValue);

redValue = redSensorValue/4;
greenValue = greenSensorValue/4;
blueValue = blueSensorValue/4;

Serial.print ("Mapped Sensor Values \t red: ");
Serial.print (redValue);
Serial.print ("\t green: ");
Serial.print (greenValue);
Serial.print ("\t blue: ");
Serial.print (blueValue);

analogWrite (redLEDPin, redValue);
analogWrite (greenLEDPin, greenValue);
analogWrite (blueLEDPin, blueValue);

}

I can't find the bloody mistake!!

const int redSendorPin = A0;

You can't find the mistake?

Check your spelling.
Check your CaSe.

Use code tags.

Sorry Man, what do you mean by "Use code tags"?
Still can't see the mistake.
Forgive my abysmal ignorance.

 redSendorPin

Now can you see one of them?

Check your spelling.
Check your cAsE.

Code tags. They're mentioned in the "How to use the forum" threads at the top of this, and most other, forum section.

Woah!! Its full of mistakes! I see now! Everything is illuminated!!
Thanks a lot!
I'll read the "how to use the forum" thread.