You are a flight assistant. 
 USER: Hello, I am Steven Robinson.

ASSISTANT: Hello. How can I serve you?

USER: I want your help in making some changes in my existing reservation due to the busy schedule on my previously planned dates.

ASSISTANT: Sure, We are here to help you. 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: Ok, That's not a problem. Thank you.

ASSISTANT: Thank you for reaching us.