Fade LEDs one by one with potentiometer

Hey!
I have 4 LEDs that I want to fade in in sequence. So first Led1, then Led2, then Led3 and then Led4. but I want to make it with one twist on the potentiometer.
So first ¼ should be Led1 to full, then stay there when Led2 fades in on the 2/4 and so on.

But I haven't found a way to tell them what part of the potentiometer's values they should lid on.
Any one have a solution, or a article I can read on the subject?

Thanks
The code so far: (LEDs named after color, and a lot of code just copied, so it's some tips in it... :-[ )

int ledR = 9;  
int ledY = 6;
int ledG = 5;
int ledB = 3;// the pin that the LED is attached to
int brightness = 0;    // how bright the LED is
int analogPin = 0;   // potentiometer connected to analog pin 3
int val = 0;         // variable to store the read value
int fadeAmount = 0;

void setup()  { 
  // declare pin 9 to be an output:
  pinMode(ledR, OUTPUT);
  pinMode(ledY, OUTPUT);
  pinMode(ledG, OUTPUT);
  pinMode(ledB, OUTPUT);
} 

void loop()  { 
  val = analogRead(analogPin);   // read the input pin

  analogWrite(ledR, val / 4);  // analogRead values go from 0 to 1023, analogWrite values from 0 to 255
  analogWrite(ledY, val / 4); 
  analogWrite(ledG, val / 4); 
  analogWrite(ledB, val / 4); 
}

Are you saying you want them to fade 255 to zero in sequence?
At the start all LEDs are at 255, full on.
So first LED fades down to zero, then second LED fades down from 255 to zero?

1023/4 is 4 steps of 255.

One way to get it done is to use the map function.

if pot value is <= 255
LED1 = pot value

if pot value is >255 and <510
LED1 = fully on
LED2 = map(LED2, 255, 510, 0, 255)

numbers progress up to 1023......