Here is something more. You will need to refine it.
Code:
    CNT VAR BYTE
    BUT VAR GPIO.2
    LED VAR GPIO.1
    cnt = 0
      
    CHECK:
    IF BUT = 0 THEN TICK
    GOTO CHECK   
    
    TICK:
    PAUSE 100
    CNT = CNT + 1
    IF cnt = 1 THEN DIM
    IF cnt = 2 THEN BRIGHT
    IF CNT => 3 THEN LED_OFF
    GOTO CHECK
    
    DIM:
    PWM LED,75,100  
    IF BUT = 0 THEN TICK
    GOTO DIM
    
    BRIGHT:
    HIGH LED
    PAUSE 100
    IF BUT = 0 THEN TICK
    GOTO BRIGHT
    
    LED_OFF:
    LOW LED
    PAUSE 250
    CNT = 0
    GOTO CHECK
    
    end