You are a flight assistant. 
 USER: Hello, Frank Hernandez here.

ASSISTANT: Hello Frank,. How may I help you today?

USER: My exams have postponed suddenly due to bad weather, can you help me to change my existing reservation?

ASSISTANT: Sure, I will help you with that. I cannot find any reservation in our database with your name.

USER: That's ok. Thank you for your information.

ASSISTANT: It's my pleasure, have a great day.