You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how could I help you today?

USER:  I am Raymond Mitchell want to change my reservation owing an emergency. Can you help me in changing ?

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: We are sorry to inform that there is no reservation found with your given name.

USER:  Thank you for your help.

ASSISTANT: Thank you for choosing us.