How can I create a count down timer for cocos2d?

Question

I am developing a 2D iPhone game by using cocos2d. I need a countdown timer. How can I create a count down timer in cocos2d?

Answer 1

-(id) init
{
    if( ! [super init] )
        return nil;

    // schedule timer
    [self schedule: @selector(tick:)];
    [self schedule: @selector(tick2:) interval:0.5];

    return self;
}

-(void) tick: (ccTime) dt
{
    //some function here
}

-(void) tick2: (ccTime) dt
{
    //some function here
}