"Ding! Ding!" joke

A woman's husband has died. After a few months, she decides she wants a new one. She submits a classified ad as follows:
"Widow looking for a new husband. To be considered, you must conform to these three criteria:
1 - You can't beat me (as my first husband did).
2 - You can't run around on me (as my first husband did).
3 - You MUST be good in bed (as my first husband wasn't)."
A few days later, the doorbell rings. She opens the door and a man without any arms and or legs is sitting in a wheel chair.
"Can I help you?" she says.
"I'm here about your ad in the paper."
"Which ad is that?"
"The one looking for a husband."
She says, "Uhm, well, there were certain criteria..."
"Yes, I know. Obviously, I could never beat you... I have no arms."
"Well, yes, I see that... but there were other criteria."
"And, as you can see, I could never run around on you... I have no legs."
"Well, yes, that's true... but there was one other thing that is very important..."
"Ah, yes, well... how do you think I rang the door bell?"