You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello,may I know your name please?

USER: This is Helen Allen, could you help me to book a flight ticket?

ASSISTANT: Sure,please provide me the details regarding the booking.

USER: Yes sure. I have planned for a holiday trip from PHX to PHL.

ASSISTANT: OK,will you please provide me the dates?

USER: I have planned for travel on 01/27 and 01/29.

ASSISTANT: OK,just hold on.

USER: Sure.

ASSISTANT: I am really sorry Helen because there is no flight available on your provided information.

USER: Oh! OK. Anyway, thank you for your help.

ASSISTANT: Thank you for contacting us.

USER: You are welcome.