You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I support you?

USER:  I am looking for a direct flight, within the fare 500. Can you help me in booking a ticket?

ASSISTANT: Sure, I can help you in finding a best flight matching your request. May I know where are you heading to?

USER: I am heading to San Francisco, CA-SFO.

ASSISTANT: When are you planning to reach there?

USER: I am planning to start on 05/07.

ASSISTANT: Can you share your source airport code as well?

USER: Sure, My source is at NC-CLT.

ASSISTANT: When would you like to return to CLT?

USER: I would like to return on 05/09.

ASSISTANT: May I know your name?

USER: I am Edward Mitchell.

ASSISTANT: Thanks for sharing your details. Unfortunately, there are no flights available at this moment.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for opting us.