You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: My name is Carol Hall. Can you help me to book a flight ticket from DFW to SFO?

ASSISTANT: Sure, I will help you. Please provide me your travel dates.

USER: Ok, please book for the dates Jan 25 and Jan 27 respectively.

ASSISTANT: Ok, please let me know your class preference.

USER: Ok, please book any class available.

ASSISTANT: Ok, do you have any specifications?

USER: Please book a connecting flight and had planned to return during afternoon.

ASSISTANT: Sorry, there is no flight available as per your requirements.

USER: That is ok, thank you for the help provided.

ASSISTANT: You are welcome and thank you for choosing us.