arduino 3 digit 7 segment timer.. code

/*
okay so this code is used for a 3 digit 7 segment display multiplexed.
it counts down from 900 (seconds) to 0, in the begining it turns on pin 13 (which is a npn transistor controlling a relay)

the segments are common anode, the way its controlled is by 3 pnp transistors on the anodes and 7 npn on the cathodes.
*/

unsigned long timeStart;        //setting up the variables used globaly
boolean lastButton = LOW;
boolean currentButton = LOW;
int Disp1 = 2;                  // setting up the pins for the displays
int Disp2 = 3;
int Disp3 = 4;
int segA = 5;
int segB = 6;
int segC = 7;
int segD = 8;
int segE = 9;
int segF = 11;
int segG = 10;
int relay = 13;                // setting up the pin for the relay
int button = 12;               // setting up the pin for the button

void setup()                    //setting up the pins for the segments button and relay
{
  pinMode(Disp1, OUTPUT);
  pinMode(Disp2, OUTPUT);
  pinMode(Disp3, OUTPUT);
  pinMode(segA, OUTPUT);
  pinMode(segB, OUTPUT);
  pinMode(segC, OUTPUT);
  pinMode(segD, OUTPUT);
  pinMode(segE, OUTPUT);
  pinMode(segF, OUTPUT);
  pinMode(segG, OUTPUT);
  pinMode(button, INPUT);
  pinMode(relay, OUTPUT);
}

boolean deBounce (boolean last)          //a debounce function as shown in sciguy14´s arduino tutorial 06
{                                        //( http://www.youtube.com/watch?v=g0pSfyXOXj8 )
  boolean current = digitalRead(button);
  if (last != current)
  {
    delay(5);
  current = digitalRead(button);
  }
  return current;
}

void number(int var)
{
  switch(var)
  {
    case 0:
    digitalWrite(segG, LOW);
    digitalWrite(segA, HIGH);
    digitalWrite(segB, HIGH);
    digitalWrite(segC, HIGH);
    digitalWrite(segD, HIGH);
    digitalWrite(segE, HIGH);
    digitalWrite(segF, HIGH);
    break;

    case 1:
    digitalWrite(segA, LOW);
    digitalWrite(segD, LOW);
    digitalWrite(segE, LOW);
    digitalWrite(segF, LOW);
    digitalWrite(segG, LOW);
    digitalWrite(segB, HIGH);
    digitalWrite(segC, HIGH);
    break;

    case 2:
    digitalWrite(segC, LOW);
    digitalWrite(segF, LOW);
    digitalWrite(segA, HIGH);
    digitalWrite(segB, HIGH);
    digitalWrite(segG, HIGH);
    digitalWrite(segE, HIGH);
    digitalWrite(segD, HIGH);
    break;

    case 3:
    digitalWrite(segF, LOW);
    digitalWrite(segE, LOW);
    digitalWrite(segA, HIGH);
    digitalWrite(segB, HIGH);
    digitalWrite(segG, HIGH);
    digitalWrite(segC, HIGH);
    digitalWrite(segD, HIGH);
    break;

    case 4:
    digitalWrite(segA, LOW);
    digitalWrite(segE, LOW);
    digitalWrite(segD, LOW);
    digitalWrite(segF, HIGH);
    digitalWrite(segG, HIGH);
    digitalWrite(segB, HIGH);
    digitalWrite(segC, HIGH);
    break;

    case 5:
    digitalWrite(segB, LOW);
    digitalWrite(segE, LOW);
    digitalWrite(segA, HIGH);
    digitalWrite(segF, HIGH);
    digitalWrite(segG, HIGH);
    digitalWrite(segC, HIGH);
    digitalWrite(segD, HIGH);
    break;

    case 6:
    digitalWrite(segB, LOW);
    digitalWrite(segA, HIGH);
    digitalWrite(segF, HIGH);
    digitalWrite(segE, HIGH);
    digitalWrite(segD, HIGH);
    digitalWrite(segC, HIGH);
    digitalWrite(segG, HIGH);
    break;

    case 7:
    digitalWrite(segF, LOW);
    digitalWrite(segG, LOW);
    digitalWrite(segE, LOW);
    digitalWrite(segD, LOW);
    digitalWrite(segA, HIGH);
    digitalWrite(segB, HIGH);
    digitalWrite(segC, HIGH);
    break;

    case 8:
    digitalWrite(segA, HIGH);
    digitalWrite(segB, HIGH);
    digitalWrite(segC, HIGH);
    digitalWrite(segD, HIGH);
    digitalWrite(segE, HIGH);
    digitalWrite(segF, HIGH);
    digitalWrite(segG, HIGH);
    break;

    case 9:
    digitalWrite(segE, LOW);
    digitalWrite(segG, HIGH);
    digitalWrite(segF, HIGH);
    digitalWrite(segA, HIGH);
    digitalWrite(segB, HIGH);
    digitalWrite(segC, HIGH);
    digitalWrite(segD, HIGH);
    break;

  }
}


void loop()
{
  digitalWrite(Disp1, HIGH);
  digitalWrite(Disp2, HIGH);
  digitalWrite(Disp3, HIGH);

  //currentButton = deBounce(lastButton);                  //Using the debounce function to see if the button has been pushed
  //if (lastButton == LOW && currentButton == HIGH)
  //{

    delay(10000);

    digitalWrite(relay, HIGH);                              //turns on the relay

    for(int x=900; x >=0; x--)                           //starts the timer at 900 seconds
    {
      int A = x/100;                                     //splits the int x (the current second) into three individual int´s
      int B = x/10 - A*10;                               //needed to send to the displays
      int C = x - A*100 - B*10;
      timeStart = millis();                              //sets the unsigned long timeStart to the current millis()
                                                         //(read about millis on the arduino site)

      while ((millis() - timeStart) <= 1000)             //runs this loop while millis() - timeStart) is less than or equal to 1 second
      {


        digitalWrite(Disp1, LOW);
        digitalWrite(Disp2, HIGH);
        digitalWrite(Disp3, HIGH);
        number(A);
        delay(5);


        digitalWrite(Disp1, HIGH);
        digitalWrite(Disp2, LOW);
        digitalWrite(Disp3, HIGH);
        number(B);
        delay(5);


        digitalWrite(Disp1, HIGH);
        digitalWrite(Disp2, HIGH);
        digitalWrite(Disp3, LOW);
        number(C);
        delay(5);


      }
    }

    digitalWrite(relay, LOW);
  //}
}