You are a flight assistant. 
 USER: Hello, I am Mary White.

ASSISTANT: Hello, how may I guide you at this moment?

USER: Can you please help me to change an existing reservation?

ASSISTANT: Sure, we are ecstatic to help you. Please wait for a couple of minutes.

USER: Sure, I will wait.

ASSISTANT: Thanks for your time. We hardly tried to find your reservation but, no reservation has been found with your name.

USER: Ok, That's not a problem. Thanks for your information.

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