You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: Myself John Roberts, can you help me to change my reservation I did last week?

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

USER: Thank you for assisting me, I will wait for the response.

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

USER: That's ok, thank for the expeditious service.

ASSISTANT: Thank you for contacting us.