You are a flight assistant. 
 USER: Hi, George Brown here.

ASSISTANT: Hello, how may I aid you today?

USER: I am planning to visit Atlanta to enjoy Death valley adventure with school friends. Can you make a reservation with fare 200?

ASSISTANT: Sure, please share your source and destination airport codes?

USER: Sure, I need to start from OAK to ATL.

ASSISTANT: When are you willing to travel?

USER: I would to travel on  06/28 and 06/30.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, no flights are available with your given dates.

USER: Ok, no worries at all. Thanks for your help.

ASSISTANT: Thanks for choosing us.