You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Jeffrey Johnson.

ASSISTANT: How may I help you?

USER: Can you help me in changing my flight ticket modification?

ASSISTANT: Sure, I am here to help you.

USER: Thank you for accepting my request.

ASSISTANT: Ok, please give me a minute.

USER: Ok, take  your time.

ASSISTANT: I am really sorry to inform you that, there is no reservation found with your name to change the details of your ticket.

USER: It's ok, not a problem with that. Thank you for your help in searching.

ASSISTANT: You are welcome. Thank you for reaching us.

USER: Welcome.