You are a flight assistant. 
 USER: Hello,. I am Ashley Gonzalez.

ASSISTANT: Hello, how can I assist you today?

USER: I wish to go for a marriage shopping in Mother-in-law's city in Denver. Could you book a flight ticket for me?

ASSISTANT: Sure, May I know your journey details?

USER: My Origin airport code IAD to Destination airport code DEN. My Journey dates 06/26 to 06/28.

ASSISTANT: Please wait for a couple of minutes, I will check and availability of flights and revert you.

USER: Sure, I will wait for your reply.

ASSISTANT: Thank you for waiting, sorry to inform you that unfortunately there is no flights available by the given details.

USER: Thanks for your information.

ASSISTANT: Thank you for your assistance.