You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you today?

USER: Can you please help me in changing my recent reservation?

ASSISTANT: Sure, I will help you. Please help me with your name.

USER: Myself John Thomas.

ASSISTANT: Please allow me a minute.

USER: Sure.

ASSISTANT: John Thomas, I am really sorry to inform you that there is no booking found on your name.

USER: Thank you for your information.

ASSISTANT: Thank you for understanding. Thank you for reaching us. Have a great time.