You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you at this moment?

USER: I am George Anderson. Due to my health problem I want to change my reservation, can you please help me that?

ASSISTANT: Sure, I am here to help you Anderson, please wait for a minute to check the reservation details in our database.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, based on your request I could not find any reservation with your name in our database.

USER: Ok, no problem. Thank you.

ASSISTANT: My pleasure, have a nice day.