You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I serve you?

USER: Due to heavy rain, I want to change my reservation. Can you help me?

ASSISTANT: Sure, we will help you. Can I have your name please for checking your details?

USER: Gregory Perez here.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Unfortunately there is no reservation found on your name to proceed further.

USER: No problem, Thank you.

ASSISTANT: Thank you for reaching us.