You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,.

USER: I am Melissa Green.

ASSISTANT: How can I aid you today?

USER: My CA exams got postponed so I need to change my existing reservation, Can you please help me with that?

ASSISTANT: Sure, we are here to help you. Please, stay online.

USER: Sure.

ASSISTANT: Thanks for your time. There is no reservation found with your name in our database.

USER: Ok, no problem.

ASSISTANT: Thank you for opting us.

USER: Thanks for your information.