You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Joseph Jackson want to change my reservation owing an emergence. Can you help me in changing?

ASSISTANT: I can help you with that. Please wait for a while.

USER: Ok.

ASSISTANT: Joseph, there is no reservation found under your name to do modifications in that.

USER: Ok, no issues. Thank you for availing me.

ASSISTANT: Thank you for choosing us.