You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I would like to return in the evening time, Could you please help me with booking a flight ticket?

ASSISTANT: Sure, I can help you in that. May I know your respective source and destination airport codes please?

USER: Sure, my airport codes are IAH and DFW.

ASSISTANT: On which dates are you planning to depart and return?

USER: May 3 and May 5 are my travelling dates.

ASSISTANT: Can I have your good name please?

USER: I am Christine Hall.

ASSISTANT: May I know in which class and airlines do you prefer to travel?

USER: I am comfortable with any class.

ASSISTANT: Do you need any stopover in between your journey?

USER: Yes.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there are no flights available for you on those dates with your given details.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for choosing us, have a nice day.