press button to switch light on and off (please help help help)

Please can someone explain me simply what i supposed to add to the code bellow so when i press button once: the light will go up and when i press second time it will go off.
i know its probably silly for you guys but i have just started with arduino and this drive me crazy

const int led=2;
const int button = 8;

void setup()

{
pinMode (led, OUTPUT);
pinMode (button, INPUT);
digitalWrite(button, HIGH);
}
void loop() {

if (digitalRead(button)==LOW){digitalWrite(led, HIGH);}

else{digitalWrite(led,LOW);}

}

something like this State Change example:

const int led=2;
const int button = 8;
int lastButtonState;
//
void setup() 
{
  pinMode (led, OUTPUT);
  pinMode (button, INPUT_PULLUP);
}
//
void loop() 
{
  int buttonState = digitalRead(button);
  if (buttonState == LOW && lastButtonState == HIGH)
  {
    delay(25);  // EDIT: added a little debounce
    digitalWrite(led, !digitalRead(led));
  }
  lastButtonState = buttonState;
}

There is a state change example already built into the arduino IDE.

There are lots of other useful examples there, see File -> Examples .....