My briggs and stratton (Troy Blit) is not cranking.

Hi.

I'm new to this forum, so forgive me if I don't provide you with accurate information.

Okay, so, I was just mowing and it ran out of gas. Well, I put more gas in it. It cranked - but, like in 10 seconds it idled down. It now wont crank. When it does, it idles down.

How do I fix?