Laser Maze with laser diodes, photo resistors and a relay

Hi,
I want to build a laser maze game like this:

I want to switch an relay instead of a servo. Need some help wth the arduino code:

#include <Servo.h>
// servo will be used to flip a switch on the red beacon light
Servo myservo;
// constants to set up pins
int mySensors = {A0, A1, A2, A3, A4, A5}; // analog pins with CDS cells to detect laser beam
const int numSensors = 4; // total number of CDS cells used ###MODIFY IF NEEDED###
// variables to handle analog values from CDS cells
int curValue; // stores the value of the CDS cell that is currently being read
int prevValue[numSensors]; // stores the previous value of each CDS cell
int baseValue[numSensors]; // stores a baseline value for each CDS cell when the laser beam is not broken
int shouldAlarm[numSensors];// flag to decide if alarm signal should be sent
int sensitivity = 35; // an offset from the baseValue to determine if laser beam is broken ###MODIFY IF NEEDED###
int sendAlarm = 0; // determines if we should send the alarm signal to the COM port
// variables to control red beacon light
int alarmLength = 3000; // how long red light should remain on in milliseconds - synch with mp3 played by processing ###MODIFY IF NEEDED###
unsigned long alarmTime;// time alarm was activated
int onPos = 50; // on position for servo ###MODIFY IF NEEDED###
int offPos = 110; // off position for servo ###MODIFY IF NEEDED###
void setup() {
// initialize the serial communication to PC
Serial.begin(9600);
// Serial messages sent to processing. The digit in the ones place tells us what kind of data we have.
// ####0 - data from A0, where #### is the data and 0 is the code telling where the data belongs
// ####1 - data from A1
// ####2 - data from A2
// ####3 - data from A3
// ####4 - alarm trigger value for A0, where #### is the value and 4 is the code telling where the data belongs
// ####5 - alarm trigger value for A1
// ####6 - alarm trigger value for A2
// ####7 - alarm trigger value for A3
// 8 - alarm servo on
// 9 - alarm servo off

// attach the servo to pin 9
myservo.attach(9);
myservo.write(offPos);

// set all of the CDS cell analog pins as inputs
for (int thisSensor = 0; thisSensor < numSensors; thisSensor++) {
pinMode(mySensors[thisSensor], INPUT);
}

calibrate();
}
void loop() {

// check each CDS cell to see if the laser beam is broken
for (int thisSensor = 0; thisSensor < numSensors; thisSensor++) {
curValue = analogRead(mySensors[thisSensor]);
Serial.println(curValue*10+thisSensor);

// A broken beam is detected if the current sensor value and
// the previous value are both less than the base value
// minus the sensitivity.
if (curValue < (baseValue[thisSensor] - sensitivity) && prevValue[thisSensor] < (baseValue[thisSensor] - sensitivity) && shouldAlarm[thisSensor] == 1) {
// laser beam has been broken, alarm should be sent
Serial.println(“8”);
shouldAlarm[thisSensor] = 0;
// activate servo to turn on red beacon light
myservo.write(onPos);
delay(20);
alarmTime = millis();
}
// laser beam not currently broken, so reset the alarm flag
else if (curValue > (baseValue[thisSensor] - sensitivity) && prevValue[thisSensor] > (baseValue[thisSensor] - sensitivity)) {
shouldAlarm[thisSensor] = 1;
}
prevValue[thisSensor] = curValue; // update the previous value
}
// deactivate the servo if it has been more than alarmLength
if (millis() - alarmTime > alarmLength) {
Serial.println(“9”);
myservo.write(offPos);
delay(20);
}
}
void calibrate() {
Serial.println(“CALIBRATING!”);
// for each CDS cell, average three readings together to
// calculate base value when laser beam is not broken
for (int thisSensor = 0; thisSensor < numSensors; thisSensor++) {
baseValue[thisSensor] = analogRead(mySensors[thisSensor]); // first reading
delay(20);
baseValue[thisSensor] += analogRead(mySensors[thisSensor]); // plus second reading
delay(20);
baseValue[thisSensor] += analogRead(mySensors[thisSensor]); // plus third reading
baseValue[thisSensor] /= 3; // divided by 3 to find average
Serial.println((baseValue[thisSensor]-sensitivity)*10+4+thisSensor); // last digit tells processing this is an alarm trigger value
}
}

I want to switch an relay instead of a servo. Need some help wth the arduino code:

So, what is the problem? If you know what value to write to a servo, you know whether that value is above, or below, the threshold needed to turn the relay on or off.