You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I be your helping hand today?

USER: As I am a scientist, I want to attend science festival with my students at Oakland. Can you do the reservation?

ASSISTANT: Sure, on which dates you want to make a reservation?

USER: Dates are 05/21 and 05/23.

ASSISTANT: Ok, may I know your budget?

USER: Price should not cross 200.

ASSISTANT: Ok, mention your locations please.

USER: My airport codes are DEN-OAK.

ASSISTANT: To proceed further, we need your name.

USER: Larry Collins here.

ASSISTANT: Ok, wait for a moment.

USER: Sure.

ASSISTANT: Thank you for waiting, we found a flight with a fare of 400. Are you okay with this?

USER: Do not proceed.

ASSISTANT: Ok.

USER: Thank you for kind service.

ASSISTANT: Thank you for visiting us.