You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: Due to sudden change in my trip to another location, I would like to do some changes in existing my reservation. Can you please help me out?

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

USER: Myself Kathleen Smith.

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

USER: Ok, no problem. Thank you so much.

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