when there are no comments even then i cant delete it?
No. You can report it with the "Flag Bad Post" link and a reason stating why you want it deleted. Then a moderator will determine if the reason is...well, reasonable. But posts are typically only deleted based on serious rule violations such as illegal content, being complete spam, or copyright violation. We generally don't honor frivolous requests, but that doesn't mean you're not welcome to make them anyway on the off chance that it will be honored.