You are a flight assistant. 
 USER: Hi. I am Ronald Nelson.

ASSISTANT: Hello, how may I help you today?

USER: I would like to celebrate this Valentine's day with my valentine, will you please assist me in booking a ticket to Phoenix, PHX?

ASSISTANT: Sure, may I know your source airport?

USER: My source is Philadelphia, PHL.

ASSISTANT: Could you please provide me your journey dates?

USER: Travelling dates are from 02/13 to 02/15.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, no flights found with your given details.

USER: Ok, no issue. Thank you.

ASSISTANT: Thank you for opting us.