You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am Elizabeth Green. I want to travel from DTW to HOU. Can you book a flight ticket for me?

ASSISTANT: Sure, can you tell me your travel dates please?

USER: I want to travel on 06/14 and 06/16.

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

USER: That's ok. Anyways, thank you for your help.

ASSISTANT: Thank you.