You are a flight assistant. 
 USER: Hi. I am Melissa Martin.

ASSISTANT: Hello, how can I help you today?

USER: On 02/19, I have to attend a meeting with my client at Denver. Can you help me in booking a flight ticket to Denver, DEN?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Kindly mention your take off airport code.

USER: My take off airport code is Houston, IAH.

ASSISTANT: May I know your return date?

USER: I intend to return on 02/21.

ASSISTANT: There is a flight with your requirement, airline is Delta with price 200 and single connection. Shall I proceed with booking?

USER: You can proceed.

ASSISTANT: Your booking is done.

USER: Thank you for your help.

ASSISTANT: Thanks for reaching us.