You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Gary Parker here.

ASSISTANT: How may I assist you?

USER: Due to inconvenience of my work, I want to change my reservation. Can you please help me for that?

ASSISTANT: Ok, please wait.

USER: Ok, I will wait.

ASSISTANT: Sorry to say, I did not find any reservation on your name to change.

USER: Anyway, thanks for the information.

ASSISTANT: Most welcome.