You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: Can you please help me with booking a flight ticket from SFO to IAD?

ASSISTANT: Sure, can you please share your travel dates?

USER: My travel dates are Dec 29 and 31.

ASSISTANT: May I know your connection limit?

USER: I need a connecting flight.

ASSISTANT: Do you have any other specification that you are looking for?

USER: I would like to return at evening.

ASSISTANT: May I know your name to proceed further?

USER: My name is Emily Clark.

ASSISTANT: I am sorry to inform you that there is no flight available at your request.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for contacting us.