You are a flight assistant. 
 USER: Hi. Gary Clark here.

ASSISTANT: Hello. How may I help you?

USER: I would like to visit New York but due to some personal work I want to change my location, can you help me to change my recent reservation?

ASSISTANT: Sure Gary Clark, wait a moment.

USER: Sure.

ASSISTANT: There is no reservation found with your name to change it.

USER: It's ok, thanks for your help and information.

ASSISTANT: Welcome Gary Clark.