You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How may I help you?

USER: I am Donald Moore. Can you please change my existing reservation, due to change my trip plan to another location?

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation matching with your name in our portal to make changes further.

USER: Ok, no issue. Thank you.

ASSISTANT: Thank you for reaching us.