You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I want to change my flight reservation as I am unwell, can you please help me?

ASSISTANT: Sure, can you please provide me your name?

USER: Thank you. I am Dennis Gonzalez.

ASSISTANT: Give me a moment?

USER: Sure.

ASSISTANT: Dennis Gonzalez. I regret to inform that there is no reservation by your name.

USER: Sad to hear that, thank you for checking.

ASSISTANT: Thank you for reaching us.