You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I serve you?

USER: Book a flight from IAH to PHL under a fare of 500.

ASSISTANT: Sure, May I know the travel dates?

USER: 10/30 and 11/01 are my travel dates.

ASSISTANT: May I know your name?

USER: Linda Miller is my name.

ASSISTANT: Sorry, No flights found with your preferable dates.

USER: Ok, no problem. Thanks for the information.

ASSISTANT: Thank you for opting us.