You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I am Helen Hernandez. I am planning to visit ORD, can you please help me to book a flight ticket from PHX?

ASSISTANT: Sure, can you please share your travel dates?

USER: Sure, my journey dates are Oct 27 and Oct 29.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: Is there any other specification that you are looking for?

USER: My departing time is afternoon.

ASSISTANT: Helen Hernandez, I am sorry to inform you that there is no flight available at your request.

USER: No problem, thank you for your information.

ASSISTANT: You are welcome. Thank you for reaching us.