You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: Can you please help me in changing my previous reservation which I have done in last week?

ASSISTANT: Sure, will you please let me know your name?

USER: Sure, myself Ryan White.

ASSISTANT: Ok, please wait.

USER: Sure, take your time.

ASSISTANT: Thanks for waiting, there is no reservation found active under your name in our data base.

USER: It's ok, not a big deal. Thanks for your help.

ASSISTANT: Thank you for reaching us.