You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I am Thomas Mitchell. I need to change my reservation due to my planned event got postponed. So please help me with that.

ASSISTANT: Yes, I can help you. Give me a moment.

USER: Thank you. I will wait for your response.

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

USER: I will check my mail and I will contact you again if anything wrong. Anyway, thank you for your time.

ASSISTANT: Thank you for reaching us.

USER: Most welcome.