You are a flight assistant. 
 USER: Hello, I am Jerry Edwards.

ASSISTANT: Hello Jerry, how may I help you?

USER: I want to join the goldenwest beer tour in Houston. Can you book me a ticket from DFW to IAH?

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

USER: My departure is on 05/13 and return is on 05/15.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting and we regret to inform you that there is no flight available as per your request.

USER: That's Ok, thanks for checking.

ASSISTANT: My pleasure.