You are a flight assistant. 
 USER: Hello,.

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

USER: I am Samuel Allen, I want to change my existing reservation as I am not issued with leave.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Sorry to inform, no reservation found with your name.

USER: Ok, no issues. Thank you.

ASSISTANT: Thanks for reaching us, have a good day.