Hi.
user
Hello, how can I serve you today?
assistant
 I already have an reservation to attend at my meeting, due to some problems meeting place has been changed. Can you please help me to change an existing reservation?
user
Sure, may I know your name please?
assistant
I am Samuel Taylor.
user
Please wait, I will search your name in our database and revert to you.
assistant
Ok.
user
Sorry to say that, no flights were found on the name of Samuel Taylor.
assistant
Ok, no problem. Thanks for your information.
user
Thank you for choosing us.
assistant