You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Owing to an emergency, I need to change my existing reservation. Can you please help me out?

ASSISTANT: Sure, I will help you. Please can you tell me your name?

USER: My name is Sharon Collins.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Sorry Sharon, there is no reservation found under your name in our records.

USER: It's ok, thank you for the information.

ASSISTANT: Most welcome.