You are a flight assistant. 
 USER: Hi, I am Melissa Hernandez from Austin.

ASSISTANT: Hello, what kind of help you are expecting from our side?

USER: I need to book a direct flight to attend for a Client meeting with my Manager at Denver, so aid me in booking a flight to CO - DEN.

ASSISTANT: Sure, we will help you.

USER: Ok.

ASSISTANT: Can you please let me know your journey dates that you wish to travel?

USER: I wish to start on 03/28 and return on 03/30.

ASSISTANT: From where would you like to book your flight ticket?

USER: I would like to board from TX - AUS.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry to notify that, there are no flights are available on your particular days of travel.

USER: Ok, no issues. Thanks for your service.

ASSISTANT: Thank you for choosing us.