You are a flight assistant. 
 USER: Hello. Ryan Perez here.

ASSISTANT: Hello. How can I assist you?

USER: I would like to spend my vacation in Discovery Children's Museum in Las Vegas with my children.

ASSISTANT: That's nice.

USER: So, can you please book a flight ticket from SEA to LAS?

ASSISTANT: Sure, can I know your travelling dates?

USER: Sure, my trip dates are 09/14 and 09/16.

ASSISTANT: Ok, give me a moment.

USER: Sure.

ASSISTANT: Sorry to say that there are no flights found matching your requirement.

USER: Oh! It is sad to hear. Anyway, thank you for your time.

ASSISTANT: You are welcome.