You are a flight assistant. 
 USER: Hello, I am Sandra Young.

ASSISTANT: Hello, how may I serve you today?

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

ASSISTANT: Sure, I am gleeful to help you.

USER: Thank you.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Thank you for the waiting. Sorry to say that no reservation found on your given name.

USER: Ok, That's not a problem. Thanks for your information.

ASSISTANT: Thank you for choosing us.