You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I be your helping hand?

USER: I am Melissa Collins. I want to change my reservation due to prepone of my examination. Can you please help me?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Please wait for a couple of minutes.

USER: Sure.

ASSISTANT: Thank you for being patient. We did not find any reservation on your name.

USER: Thank you for informing me.

ASSISTANT: Thank you for reaching us.