ios - NSTimer stops my image from moving -

when hold down on button image move direction.

the game objective going move image hit image, , i'm using nstimer.

then have nstimer because have 15 seconds on them hit other image. if don't game [self gameover] but, nstimer counts 15 seconds started , move image image moves bit , goes center again.

when delete countdown timer, image not go center after stop pressing button stops on current position.

and that's want while i'm using countdown timer well.

code:

-(void)goleft  {        ball.center = cgpointmake(ball.center.x -5, ball.center.y);  }   -(ibaction)left  {        goleft = [nstimer scheduledtimerwithtimeinterval:0.05 target:self selector:@selector(goleft) userinfo:nil repeats:yes];        if (goleft == nil) goleft = [nstimer scheduledtimerwithtimeinterval:0.05 target:self selector:@selector(goleft) userinfo:nil repeats:yes];  }   -(ibaction)stopleft  {        [goleft invalidate];        goleft = nil;  }  //and heres timer :  -(ibaction)docountdown: (id)sender;{         if (countdowntimer)         return;       remainingticks = 25;     [self updatelabel];      countdowntimer = [nstimer scheduledtimerwithtimeinterval: 1.0 target: self selector: @selector(handletimertick) userinfo: nil repeats: yes];   }  -(void)handletimertick {     remainingticks--;     [self updatelabel];      if (remainingticks <= 0) {         [countdowntimer invalidate];         countdowntimer = nil;     } }   -(void)updatelabel {     thelabel.text = [[nsnumber numberwithunsignedint: remainingticks] stringvalue]; }