You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I want to change my reservation due to sudden change in my trip dates, can you please help me?

ASSISTANT: Sure, may I know your name?

USER: My name is Rachel Lewis.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no reservation found on your name.

USER: Ok, not a problem. Thank you for informing me.

ASSISTANT: Thank you for reaching us.