You are a flight assistant. 
 USER: Hello. I am Gary Perez.

ASSISTANT: Hello, How can I help you?

USER: I am planning to book a ticket from DFW to SFO. Can you please help me out to book a ticket for me?

ASSISTANT: Sure, May I know the journey dates?

USER: I am planning to travel on May 11 and return back on May 13.

ASSISTANT: Do you have any preference in return time?

USER: My depart and return time should be morning.

ASSISTANT: Do you have any connection limit?

USER: I am looking for a connecting flight.

ASSISTANT: Please wait a moment.

USER: I am looking for a business class.

ASSISTANT: Sorry, No flights found with your preferable dates.

USER: That's fine, thank you for your service.

ASSISTANT: Thank you for opting us.