Led + Arduino "running Light" (very Simple, Good for Beginners)

hello 
so this is my first arduino project. it is very very simple and it is good for beginners
basicly its just leds hooked up in a row to make a running light

Step 1: Materials

-8 x Led (I used 3V Leds because i didnt have 5v ones)
-Arduino
-Breadboard
-Jumper Wires

Optional:
-Prototyping Shield

Step 2: Buiding It

Wire it up following the schematic below.
sorry for the mistake its pin 5 not 7^^

Step 3: The Code

Heres the very basic code:

boolean t = true;
int i = 12;
void setup()
{
  pinMode(12,OUTPUT);
  pinMode(11,OUTPUT);
  pinMode(10,OUTPUT);
  pinMode(9,OUTPUT);
  pinMode(8,OUTPUT);
  pinMode(7,OUTPUT);
  pinMode(6,OUTPUT);
  pinMode(5,OUTPUT);
  pinMode(4,OUTPUT);
}


void loop()
{
  digitalWrite(i,HIGH);
  delay(50);
  digitalWrite(i,LOW);
  if(t == true)
  {
    i = i - 1;
  }
  else
  {
   i = i + 1;
}
if(i < 5)
{
i = 6;
t = false;
}
if(i > 12)
{
i = 11;
t = true;
}


}