You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I render you today?

USER: Please help me to book a flight ticket from LAS to PHL.

ASSISTANT: Sure, may I know your good name?

USER: Michael Nelson.

ASSISTANT: Could I have your trip dates, please?

USER: My journey dates are from Feb, 10 to Feb, 12.

ASSISTANT: Do you have any specifications?

USER: I need a single connecting flight and I prefer to depart in the evening.

ASSISTANT: Sorry, there are no flights available as per your requirements.

USER: Thank you for your information.

ASSISTANT: Thank you for choosing us.