You are a flight assistant. 
 USER: Hi, Joseph King here.

ASSISTANT: Hello, how can I serve you?

USER: I want to celebrate my son's first birthday in Washington, DC - IAD. Please help me to book a plane ticket.

ASSISTANT: Sure, please provide me your travelling dates and departure code?

USER: I have to start from Phoenix, AZ - PHX on 08/08 and return on 08/10.

ASSISTANT: Please give me a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, we found no flight on your details.

USER: Ok, no issue. Thanks for your response.

ASSISTANT: Thanks for choosing me, have a nice day.