You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: Can you please help me to change my existing reservation as my trip got postponed?

ASSISTANT: Sure, may I know your name to check your details in our reservation list?

USER: Sure, my name is Sharon Thomas.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Thank you for waiting Sharon Thomas, sorry to inform you that there is no reservation found on your name to do modifications.

USER: Not an issue, thank you for checking it.

ASSISTANT: Thank you for reaching us.