You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Debra Davis here.

ASSISTANT: How may I help you?

USER: Could you like to book me a flight ticket from PHL to SFO?

ASSISTANT: Sure, I am glad to help you. Could you please share your trip dates?

USER: My trip dates are Dec 20 and Dec 22.

ASSISTANT: May I know your connection limit please?

USER: I require a stopover in between my journey.

ASSISTANT: Is there any class preferences?

USER: I would like to travel in economy class.

ASSISTANT: May I know your depart and return timings?

USER: My return time should be in the evening.

ASSISTANT: Do you have any other specifications?

USER: I prefer my journey in normal cost.

ASSISTANT: Sorry, there are no flights found on your trip dates.

USER: Ok, not a problem. Thank you for your information.

ASSISTANT: Thank you for reaching us.