You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Kimberly Johnson.

ASSISTANT: How may I guide you today?

USER: I want to travel from IAH to OAK. Can you book a flight ticket for me?

ASSISTANT: Sure, I will help you with that. Can you please share your journey dates?

USER: I want to travel in the flight on 05/23 and 05/25.

ASSISTANT: Wait for a minute.

USER: Ok.

ASSISTANT: I am sorry to say that there is no flight found.

USER: That's ok.

ASSISTANT: Thank you for contacting us.

USER: Anyways, thank you.