You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to change my existing reservation, as my exams got postponed. Can you please help me out with it?

ASSISTANT: Can you please provide me your name where I can check the system.

USER: My name is Patrick Williams.

ASSISTANT: Give me a moment.

USER: Ok, sure. Take your own time.

ASSISTANT: Patrick Williams. I regret to inform that there is no reservation found by your name.

USER: Ok, no problem. Anyways, thank you for the information.

ASSISTANT: Thank you for reaching us.