You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Margaret Hernandez here. I want to meet my business partner to discuss about some issues in our casino. Please book my ticket from IAH to LAS.

ASSISTANT: Sure, may I know your travel dates please?

USER: My trip dates are 04/12 and 04/14.

ASSISTANT: Thanks for waiting. But I am sorry to say that there are no flights available.

USER: It's ok, thank you.

ASSISTANT: Thank you.