You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I assist you?

USER: I am Charles Gonzalez. I want to book a flight ticket to attend International Conference on Social Issues in Denver, CO - DEN. Can you please make a flight reservation from Dallas & Fort Worth, TX - DFW?

ASSISTANT: Sure, let me know your travelling dates?

USER: My planned journey dates are 10/07 - 10/09.

ASSISTANT: Please provide your specifications.

USER: I can afford up to 500.

ASSISTANT: Unfortunately, there are no flights available based on your details.

USER: Ok, not a problem. Thanks for your kind response.

ASSISTANT: Thank you for choosing us.