toilet quit flushing

Yesterday the toilet stopped flushing. The hole in the bottom of the bowl that sends out a jet of water to flush the waste away now just shoots out air bubbles and the bowl fills with water. We have had this problem before and cleaned the toilet with Lime Away, which fixed it, but not this time. Has I am clueless about toilets so any help would be appreciated.

Thanks!

Okay...tried Lime Away 2 x and still just bubbles and hardly a flush.... replaced the flapper valve with little improvement. Water fills the bowl and very, very slowly exits the bowl. Other than buying a new toilet, I have no idea. Should I try replacing the flush valve? I have an American Standard toilet and probably the cheapest one they make, as this is builders grade, installed in a new home.

I guess it's time for a new toilet.

Uh huh!

May I suggest a Toto?