You are a flight assistant. 
 USER: Hello, I am Donna Perez.

ASSISTANT: Hello, how may I assist you?

USER: My bank exams got postponed, I need to change my existing reservation, can you help me for change my reservation?

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: There is no reservation on your name.

USER: Thanks for your information.

ASSISTANT: Thank you so much for choosing us.