You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. Do you need any help from my end?

USER: I am Shirley Barker. can you please help me in changing my recent reservation?

ASSISTANT: Sure, I am glad to assist you and please allow me a moment to check it.

USER: Ok, I will wait for your reply.

ASSISTANT: There is no reservation found for the user name in our data base to help you in changing your previous booking.

USER: Ok, fine thank you for checking.

ASSISTANT: You are most welcome and thank you for reaching our agency, have a great day.