beginner problem with loops

// 300 seconds
var counter_timer = 300;

void count_down(){

    // while we still have to count down:
    while(counter_timer > 0){

        DEBUG_VAR(counter_timer, 10);

        // count down each second:
        counter_timer -= time_step / 16;

        wait(1);
    }

    beep();
}

while(1)
{
   if(key_a)
      do_something();
   
   wait(1);
}

var light_on = 0;
var pressed = 0;
function press_f(){
     // -- Turn the Light On
     if(key_f && pressed == 0 && light_on == 0){light_on = 1;pressed = 1;}

     // -- Turn the Light Off
     if(key_f && pressed == 0 && light_on == 1){light_on = 0;pressed = 1;}

     // -- Wait until release of key_f to allow pressed again
     if(key_f==0 && pressed == 1) {pressed = 0;}

     if(light_on == 1){
           ..//Do this
     }
     else{
           ..//Reset / stop countdown
     }
}
action flashlight(){
      while(1){
            press_f();
            wait(1);
      }
}

var flashlight_on = 0;

void toggle_flashlight()
{
	flashlight_on = 1 - flashlight_on; // toggle between 1 and 0
	
	if(flashlight_on)
	{
		// *** turn flashlight on
		
		while(flashlight_on)
		{
			// *** battery drain
		}
	}
	else
	{
		// *** turn flashlight off
	}
}


main()
{
	// blabla
	
	on_f = toggle_flashlight; // assign 'toggle_flashlight' to the [F]-key
	
	// blabla	
}

var KEY_F_LOCKEDO_OR_OPEN = 0
if(!key_f && KEY_F_LOCKED_OR_OPEN == 1)
KEY_F_LOCKED_OR_OPEN =0;
IF(key_f && KEY_F_LOCKED_OR_OPEN ==0)
{
 KEY_F_LOCKED_OR_OPEN = 1;
 .... CALL FLASHLIGHT/TIMER HERE...
}

void count_down(){
my.ambient = 100;
my.lightrange = 150;
// while we still have to count down:
while(counter_timer > 0 && key_f) // CHANGED
{

// DEBUG_VAR(counter_timer, 10);

// count down each second:
counter_timer -= time_step / 16;

wait(1);
}
my.ambient = 0;
my.lightrange = 0;

}