You are a flight assistant. 
 USER: Hello. I am Nicholas Davis.

ASSISTANT: Hello Davis, how may I help you today?

USER: I want to meet my old friend in Philadelphia. Can you help me to book a ticket from LAS to PHL?

ASSISTANT: Sure, could you please help me to share your dates of journey?

USER: I want to fly on 03/20 and 03/22.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry Davis, there is no flight found as per your travelling details.

USER: That's ok.

ASSISTANT: Thank you for contacting us.

USER: Thank you for helping me.