You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I am Lisa Thompson, want to travel from DTW to DCA. Please help me in booking my ticket.

ASSISTANT: Ok, may I know your planned dates for this journey?

USER: Sure, my travelling dates are from 11/21 to 11/23.

ASSISTANT: Lisa Thompson, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, no flights are available for your journey.

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

ASSISTANT: Thank you for choosing us.