You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Anna Robinson. I wish to do my birthday shopping in The galleria.So, will you assist me in booking a flight ticket from Washington, DCA?

ASSISTANT: Sure, please share me your travelling dates?

USER: I would like to start my journey on 08/20.

ASSISTANT: Kindly assign me your destination code?

USER: Houston, HOU is my landing point.

ASSISTANT: May I know your return date?

USER: I intend to return on 08/22.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, there were no flights with your given details.

USER: It's ok, no problem. Thank you for your kind information.

ASSISTANT: Thank you for reaching us.