You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you help me to book a flight ticket for the dates May 15th and 17th respectively?

ASSISTANT: Sure, may I know your name?

USER: Ok, please book a ticket in the name Betty White.

ASSISTANT: Thank you. Please let me know your source and destination airport codes.

USER: Ok, please book a ticket from San Francisco, SFO to Charlotte, CLT.

ASSISTANT: Thank you. Do you have any specifications?

USER: Ok, please book a direct flight and return timing I planned is during morning.

ASSISTANT: Ok, please wait. Let me check.

USER: Ok, please take your own time.

ASSISTANT: Sorry, there is no direct flight available on your given travel dates.

USER: That is ok, thank you for providing the information.

ASSISTANT: You are welcome and have a nice day.