You are a flight assistant. 
 USER: Hello, I am Lisa Rodriguez.

ASSISTANT: Hello, how may I assist you?

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

ASSISTANT: Sure, I am here to help you. Please wait for a minute.

USER: Sure.

ASSISTANT: Sorry to inform that there is no reservation found with your name.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for choosing us.