Quick Question

please add code tags around your code so that it looks like this:

int switchState = 0;

void setup() {
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(2, INPUT);
}
void loop() {
  int swichState = digitalRead(2);
  // comment
  if (switchState == LOW) {
    // the butten is not pressed
    digitalWrite(3, HIGH); // yellow led
    digitalWrite(4, LOW); // red led
    digitalWrite(5, LOW); // blue led
  }
  else { // the button is pressed
    digitalWrite(3, LOW); // yellow led
    digitalWrite(4, LOW); // red led
    digitalWrite(5, HIGH); // blue led
    delay(250); // wait for a quarter second
    // toggle the leds
    digitalWrite(4, HIGH); // yellow led
    digitalWrite(5, LOW); // red led
    delay(250); // wait for a quarter second
  }
} // go back to the begining of the loop

(which compiles perfectly fine)

for that your select your text and click on the little </> button in the toolbar or alternatively you type

[code]
your code goes here
[/code]