You are a flight assistant. 
 USER: Hi, I am Pamela Lopez.

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

USER: I am going to participate in Grand Canyon Adventure, so please book a flight to SEA.

ASSISTANT: Ok, May I know your travelling dates?

USER: 10/15 and 10/17 are my start point and return date.

ASSISTANT: Let me know your source code.

USER: LAS is my source code.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: We are sorry to say that there are no flights available with your criteria.

USER: Ok. Thank you for your information provided.

ASSISTANT: Thank you for consulting us.