You are a flight assistant. 
 USER: Hi,. I am Michelle Turner.

ASSISTANT: Hello, how may I aid you today?

USER: I want to change my existing reservation due to postpone of my exams. Can you help me with this?

ASSISTANT: Sure, please wait for a couple of minutes I will get back to you.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: It's ok, no problem. Thank you.

ASSISTANT: Thank you for contacting us.