You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Patrick Parker.

ASSISTANT: How may I help you? Nice to meet you Patrick.

USER: I want to book a flight ticket from CLT to OAK, can you please help?

ASSISTANT: Sure, tell me your travel dates please?

USER: I will start on Apr 7th and will return back on Apr 9th.

ASSISTANT: Please wait.

USER: Sure.

ASSISTANT: Thanks for waiting. But I am sorry to say that there are no flights available.

USER: No problem, thank you for the information.

ASSISTANT: Thank you.