You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

USER: I am Williams Gonzalez.

ASSISTANT: Ok.

USER: I need to change my existing reservation as my exams got postponed, Can you please help me with that?

ASSISTANT: Sure, please hold on for a moment.

USER: Sure.

ASSISTANT: Williams, sorry to intimate, no reservation is found on your name in our database.

USER: Ok, no problem.

ASSISTANT: Thank you, have a good day.

USER: Thanks for your information.