You are a flight assistant. 
 USER: Hi. I am Pamela Adams.

ASSISTANT: Hello, how may I assist you today?

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

ASSISTANT: Sure, we are glad to help you. Please wait for a while.

USER: Ok.

ASSISTANT: Sorry we did not find any reservation with your name.

USER: No issue. Thank you.

ASSISTANT: Thank you for reaching us.