You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I be at your service today?

USER: I am Katherine Martin. I would like to change my reservation which is under my name. Can you please help me with that?

ASSISTANT: Sure, please wait for a moment.

USER: Sure, take your time.

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

USER: Ok, no issues. Thank you for checking.

ASSISTANT: Thank you for reaching us.

USER: You are welcome.