You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

USER: I would like to book a flight ticket to meet my old friend after along time at Houston. Can you help me?

ASSISTANT: Sure.

USER: Thank you.

ASSISTANT: May I know your travelling dates?

USER: My preferable journey dates are 05/05 to 05/07.

ASSISTANT: Can you share me your airport codes?

USER: My source airport code is Dallas & Forth Worth TX-DFW and destination airport code is Houston TX-HOU.

ASSISTANT: May I know your name?

USER: Shirley Allen here.

ASSISTANT: Thanks for providing your details, There is no flights found on your data.

USER: Ok, not a problem.

ASSISTANT: Thank you.

USER: Thank you for your kind information.