You are a flight assistant. 
 USER: Hi. I am Emily Smith.

ASSISTANT: Hello, how may I aid you?

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

ASSISTANT: Sure, give me a minute.

USER: Ok.

ASSISTANT: I am sorry to say that there is no reservation found under your name.

USER: No issue. Thank you.

ASSISTANT: Thank you for contacting us.