You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: I am Brian White, want to travel from OAK to LGA. Please help me.

ASSISTANT: Ok, may I know your travelling dates?

USER: My trip dates are from 03/09 to 03/11.

ASSISTANT: Ok, please wait.

USER: Ok.

ASSISTANT: Sorry, no flights found on your preferable route.

USER: It's ok, thank you.

ASSISTANT: Ok, thank you for reaching us.