You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I am Benjamin Taylor, want to alter my recent reservation due to some sudden changes in my plan. Please help me out with that.

ASSISTANT: Sure, We are here to assist you.

USER: Thank you.

ASSISTANT: Please wait a while.

USER: Sure.

ASSISTANT:   Thank you for waiting, but I am sorry to say that, there is no active reservation found with your name in our database to change it.

USER: It's ok, thank you for your help.

ASSISTANT: Thank you for choosing us.