You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

USER: I want to change my existing reservation which is done recently due to some problems, can you please help me?

ASSISTANT: Sure, I am Gleeful to help you. Could you please provide your name to check your reservation status?

USER: Ok, my name is Alexander Moore.

ASSISTANT: Ok, please hold on for a moment I will check your complete reservation details and proceed further with your cancellation.

USER: Ok, I will wait for your respose.

ASSISTANT: Sorry to say, there is no active reservation on your name in my database.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us, have a nice day.

USER: Thank you for your service.