You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you at this moment?

USER: I am Lisa Williams, I want to book a flight ticket from SEA to PHL.

ASSISTANT: Sure, may I know your planned dates of journey?

USER: My planned dates are 07/16 and 07/18.

ASSISTANT: Sorry Lisa, there is no flights as per your planned dates of journey.

USER: Not a problem, anyway thank you for the help.

ASSISTANT: Most welcome.