You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: Can you please help me to change my reservation?

ASSISTANT: Sure, I will help you. Please help me with your name.

USER: My name is Margaret Lewis.

ASSISTANT: Margaret Lewis, I am really sorry to inform you that there is no booking found on your name.

USER: Ok, not a problem. Thank you for informing me.

ASSISTANT: Thank you for understanding. Thank you for reaching us. Have a great time.