you're on!

An exclamation of agreement to something that was said or that is happening, often (but not always) a challenge or a wager. A: "Want to see who can run to the end of the road the fastest?" B: "You're on!" A: "I bet you $50 that my team beats yours in the championship." B: "You're on!"

Common Names:

Name	Pronounced	Usage
Theobald	THEE-ə-bawld (English)	English (Rare), Ancient Germanic
Mykhailo	-	Ukrainian
Carlisle	KAHR-liel	English
Ambler	['æmblə]
Tamsyn	TAM-sin	English (British)
Varfolomey	-	Russian (Rare)