You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I provide assistance to you?

USER: Can you please change my travel dates in my existing reservation?

ASSISTANT: Sure, may I know your name?

USER: Thank you for your response. My name is Jack Martin.

ASSISTANT: Hold on a minute.

USER: Ok.

ASSISTANT: Sorry, we could not find any reservation on your name.

USER: Oh! It's ok no problem.

ASSISTANT: Thank you for choosing us.

USER: Thank you for your information.

ASSISTANT: Welcome.