You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Timothy Anderson.

ASSISTANT: What service that you are looking from our agency?

USER: Please help me out to change my existing reservation.

ASSISTANT: Sure, I am glad to help with that.

USER: Thank you.

ASSISTANT: Please wait a moment to check your previous reservation.

USER: Ok.

ASSISTANT: We regret to inform you that there is no reservation on your name in our records.

USER: No issues, thanq you.

ASSISTANT: Thank you for reaching us, hope you have a great day.