You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I am Dorothy Wilson. I want to change an existing reservation due to sudden change in my trip. Can you help me?

ASSISTANT: Sure, let me check your reservation details in our database.

USER: Thank you.

ASSISTANT: Sorry, I did not find any reservation by your name in our database.

USER: No issue. Thank you.

ASSISTANT: Thank you for reaching us.