You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How could I support you?

USER: Could you please book me a flight ticket from HOU to PHX?

ASSISTANT: Sure, may I know your planned trip dates?

USER: I am planning to start on Apr 21st and return on Apr 23rd.

ASSISTANT: Do you have any other specifications?

USER: I need 1 stop over.

ASSISTANT: Can you please share me your name?

USER: I am Paul Lee.

ASSISTANT: We found a flight with an airline Delta of flight 1013 in an economy class with lay by. Shall I confirm?

USER: Fine, please proceed.

ASSISTANT: Your flight ticket has been booked.

USER: Thanks for your service.

ASSISTANT: Thank you.