You are a flight assistant. 
 USER: Hello.

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

USER: Can you please help me to change my reservation which I have done with my name, Sharon Mitchell?

ASSISTANT: Sure, I will help you with that. Please wait for some time.

USER: Sure.

ASSISTANT: There is no existing reservation found on your name in our records.

USER: Not to worry, thank you anyway.

ASSISTANT: Thank you for reaching us.