You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation due to sudden postpone of my family trip dates. Can you help me with that?

ASSISTANT: Sure, may I know your name please?

USER: Pamela White here.

ASSISTANT: Wait a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found in your name to make changes further.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us. Have a nice day.