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

ASSISTANT: Hello, how can I help you today?

USER: I would like to travel from HOU to DEN. can you please help me to book a ticket?

ASSISTANT: Sure, when are you willing to travel?

USER: My travelling dates will be on 11/09 to 11/11.

ASSISTANT: Ok, any other requirements?

USER: I need a direct flight.

ASSISTANT: Ok, no flights found with your requested details.

USER: Not an issue, thank you.

ASSISTANT: Thank you for opting us.