You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: Deborah Davis here. I am a scientist, I have to submit my project work to my superiors. Could you book my ticket from IAH to OAK?

ASSISTANT: Sure, may I know your trip dates please?

USER: My itinerary dates are 03/25 and 03/27.

ASSISTANT: Do you have any specifications?

USER: No.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Thanks for waiting. Sorry, there are no flights found with your specifications.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.