You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Justin Wright.

ASSISTANT: How can I help you?

USER: I want to change my existing reservation. Can you help me in this?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry Justin Wright, no reservation found on your name in our reservation list.

USER: Not an issue, thank you.

ASSISTANT: Thank you for choosing us, have a nice day.