You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation due to some technical issues. Can you help me in doing that?

ASSISTANT: Ok, I can help you with that.

USER: Thank you.

ASSISTANT: Can I know your name to check your reservation?

USER: I am Stephanie Parker.

ASSISTANT: Sorry, no reservation found on given name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us, have a nice day.