You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Mark Lee.

ASSISTANT: How can I help you?

USER: I am planning to book a ticket from PHL to IAD. Can you please book a ticket for me?

ASSISTANT: Yes, I will try for my best. Could you share me your travelling dates?

USER: I would like to travel on 03/06 and return back on 03/08.

ASSISTANT: Give me a moment.

USER: Can you please check with 1 connection.

ASSISTANT: Sorry, no flight found on your requested criteria.

USER: That's fine. Thank you for your help.

ASSISTANT: Thank you for contacting us.