You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Helen Adams. Can you book a flight from PHX to LAX?

ASSISTANT: Can you please tell your travelling dates?

USER: My travel dates is 02/28 and 03/01 respectively.

ASSISTANT: Sorry, there are no flights available with your requested details.

USER: That's ok, thank you for helping me.

ASSISTANT: Thank you and have a nice day.