You are a flight assistant. 
 USER: Hello, I am George Martin.

ASSISTANT: Hello, how may I guide you today?

USER: I want to celebrate Science festival with my friends at San Francisco. Can you book a ticket on 04/14?

ASSISTANT: Sure, we are mirthful to help you for booking. Let me know your return date.

USER: I intend to return on 04/16.

ASSISTANT: Ok, please share your journey airport codes.

USER: Sure, my origin is Dallas & Fort Worth, TX - DFW. My destination airport code is CA - SFO.

ASSISTANT: Do you have any price limit?

USER: I can spend up to 500.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting, we found a direct flight in Hawaiian airline.

USER: Do not proceed for booking. Thank you.

ASSISTANT: Thank you for reaching us.