You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: Myself Margaret Taylor. I want to change my existing reservation, can you help me in that?

ASSISTANT: Sure, I am here to help you with that.

USER: Thank you.

ASSISTANT: Please wait for a minute.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry to say that, there is no reservation found on your name in our database.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: Thank you for reaching us.