You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I want to change my existing reservation due to bad health issues. Can you help me with that?

ASSISTANT: Please help me with your name.

USER: I am George Mitchell.

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation matching with your name in our portal to make changes further.

USER: Ok, no problem. Thank you.

ASSISTANT: Most welcome.