int id = -1;
Plugin plugin;

public void theMethodThatMovesSomeone(final Player player, final Location location){
	id = plugin.getServer().getScheduler().scheduleSyncDelayedTask(plugin, new Runnable(){
			public void run(){
				player.teleport(location);
			}
		}, 5*20);
	if(id==-1){
		// error
 	}
}

public void cancel(){
	if(id!=-1) plugin.getServer().getScheduler().cancelTask(id);
}