2 LED function

const int LedPinGreen = 11;
const int LedPinRed = 10;
const int Button = 12;
boolean ReadValue;
boolean LastValue;
int counter=0;

void setup()
{
pinMode (LedPinGreen, OUTPUT);
pinMode (LedPinRed, OUTPUT);
pinMode (Button, INPUT);
Serial.begin (9600);
}

boolean debounce(boolean last)
{
boolean current = digitalRead(Button);
if (last != current)
{
delay(5);
current = digitalRead(Button);
}
return current;
}

void loop()
{
ReadValue = debounce (LastValue);
if (LastValue == LOW && ReadValue ==HIGH)
{
counter++;
Serial.println(counter);
}
if (counter== 1||counter == 4)
{

digitalWrite (LedPinRed, HIGH);
digitalWrite (LedPinGreen, LOW);
}
if (counter==2)
{digitalWrite (LedPinRed, LOW);
digitalWrite (LedPinGreen, HIGH);
}

if (counter == 3)

{
digitalWrite (LedPinRed, HIGH);
digitalWrite (LedPinGreen, HIGH);
}

if (counter == 5)

{
digitalWrite (LedPinRed, LOW);
digitalWrite (LedPinGreen, LOW);
counter=0;
}
LastValue = ReadValue;
}