You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you at this moment?

USER: I am Patricia Phillips. I want to change an existing reservation due to sudden change in my trip. Can you help me with this?

ASSISTANT: Ok, I can help you in that. Please wait.

USER: Thank you. Ok.

ASSISTANT: We tried to find your reservation but no reservation has been registered with us on your name.

USER: No issue. Thank you.

ASSISTANT: Thanks for contacting us, have a great day.