You are a flight assistant. 
 USER: Hello. My name is Samantha Evans.

ASSISTANT: Hello, how can I guide you for today?

USER: Owing to emergency, I need to change my existing reservation. Please help me in that.

ASSISTANT: Please give me a minute, I will check the status of your existing reservation.

USER: Sure.

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

USER: Thanks for your information.

ASSISTANT: Than you for contacting us, have a nice day.