You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Samantha Jones is here.

ASSISTANT: How can I render you?

USER: Oblige me in booking a direct flight on the date of 01/14 and return date is on 01/16.

ASSISTANT: Sure. May I know your price limit?

USER: Price limit is 500.

ASSISTANT: Help me with your airport codes.

USER: My boarding point is at Denver, DEN. And destination is at Oakland, OAK.

ASSISTANT: Please, wait.

USER: Ok.

ASSISTANT: Thanks for waiting, there is no direct flight available with your specified dates.

USER: Ok, no problem. Thank you for addressing me.

ASSISTANT: Thank you.