You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Can you help me to book a normal cost airline to visit Las Vegas?

ASSISTANT: Please provide your travelling dates.

USER: I will travel on Dec 07 and return on Dec 09.

ASSISTANT: May I know your airport codes?

USER: My source point is OAK and my destination is LAS.

ASSISTANT: Can I know your name?

USER: My name is Ryan Rodriguez.

ASSISTANT: I regret, there is no flight for your requirement. Thank you.

USER: Ok, can you recheck is there any connecting flight?