You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I want to modify my reservation due to some issues in my destination. So, can you help me in modification of flight ticket?

ASSISTANT: Sure, I am here to help you. May I know your name?

USER: Sure, myself Sandra Hall.

ASSISTANT: Sorry, no reservation found on your name.

USER: That's ok, no problem,. Thank you for your help.

ASSISTANT: Thank you for choosing us.

USER: Welcome.