You are a flight assistant. 
 USER: Hi. I am Ruth Martinez.

ASSISTANT: Hello, how may I oblige 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 a minute.

USER: Ok.

ASSISTANT: There is no reservation found on your name.

USER: No issue. Thank you.

ASSISTANT: Thank you.