You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Nancy Smith, want to travel from DTW to PHL. Please help me in booking my ticket.

ASSISTANT: Nancy Smith, I am here to help you for this. When you are planning to leave?

USER: Thank you and my trip dates are from 03/18 to 03/20.

ASSISTANT: Do you have any airline preference?

USER: No, I can adjust in any of the class.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry to intimate for you, no flights are found with your criteria.

USER: It's ok, thank you for your help.

ASSISTANT: Thank you very much for reaching us.