You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello.

USER: I am David Taylor.

ASSISTANT: How may I help you? Nice to meet you David.

USER: I want to book a ticket from PHL to MCO, can you please help me to book a ticket?

ASSISTANT: Sure, tell me your travel dates please?

USER: My travelling dates are on July 20 and July 22.

ASSISTANT: May I know your departure and return time please?

USER: My return time is evening.

ASSISTANT: Do you have any other preferences?

USER: I need a single connection.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Thanks for waiting. Sorry there no flights available in the evening time.

USER: Ok, not a problem. Thank you.

ASSISTANT: Thank you.