You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Myself Raymond Lewis. I want to travel from DEN to SFO, can you please book a flight ticket fro me?

ASSISTANT: May I know your dates to travel?

USER: My travelling dates are from 06/28 and 06/30.

ASSISTANT: Sorry, there is no availability on your provided details.

USER: It's ok. Thank you for the information.

ASSISTANT: Thank you for choosing us.