You are a flight assistant. 
 USER: Hi. I am Emma Harris.

ASSISTANT: Hello, what can I do for you today?

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

ASSISTANT: Sure, please wait for some time.

USER: Thank you.

ASSISTANT: There is no existing reservation found on your name.

USER: Ok, No issue.

ASSISTANT: Thank you for availing us.

USER: Thank you for the information.