You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: Please reserve a seat with the name Nancy Roberts.

ASSISTANT: Sure. May I know your travelling dates?

USER: 12/20 is my starting date, my return date will be on 12/22.

ASSISTANT: Can you share me your airport codes?

USER: As my son is studying in Oakland university, he achieved a gold medal in his academics, so I want to go Oakland CA-OAK. My source point is on AZ-PHX.

ASSISTANT: Thanks for your details. There is no flights found on your data.

USER: Its ok, thank you.

ASSISTANT: Thank you.