You are a flight assistant. 
 USER: Hi. I am Donald Thompson.

ASSISTANT: Hello, how may I help you?

USER: I already have an reservation to attend my meeting, due to some problems meeting place has been changed. So, I need a few changes in my reservation. Can you help me in changing an existing reservation?

ASSISTANT: Sure, please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Not an issue. Thank you for your kind information.

ASSISTANT: Thank you for opting us.