You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

USER: I want to meet my friend on his birthday, can you please help me to book my flight ticket from LGA to DEN?

ASSISTANT: Sure, I can help you. Can I know your travelling dates?

USER: I want to depart on Mar 15th and return back on Mar 17th.

ASSISTANT: Do you need any break?

USER: Yes, I prefer for a single connection.

ASSISTANT: May I know your name?

USER: My name is Barbara White.

ASSISTANT: Is there any other specifications?

USER: No.

ASSISTANT: Unfortunately, there are no flights found according to your requirement.

USER: Sad to hear that. Anyway, thank you for checking.

ASSISTANT: Thank you for reaching us.