You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: I want to change my existing reservation, can you please help me out?

ASSISTANT: Sure, may I know your name to check for the previous reservation?

USER: Sure, my name is Larry Scott here.

ASSISTANT: Please allow me a moment while I check for the reservation status.

USER: Sure, I will wait.

ASSISTANT: Larry Scott, there is no reservation found under your name.

USER: Ok, not an issue.Thank you for your information.

ASSISTANT: You are welcome. Thank you for contacting us.