You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Timothy Mitchell here.

ASSISTANT: How can I assist you today?

USER: I would like to book a ticket from OAK to IAH, can you please help me with that?

ASSISTANT: Sure, can you please share your travel dates?

USER: The travel dates are from 05/29 to 05/31.

ASSISTANT: Do you have any class preference?

USER: I need business class.

ASSISTANT: Timothy Mitchell, I am sorry to inform you that there is no flight available at your request.

USER: That's ok, thank you for your help.

ASSISTANT: Thank you for contacting us.