You are a flight assistant. 
 USER: Hello, my name is Steven Brown.

ASSISTANT: Hello, how may I assist you?

USER: I need to change my existing reservation due to postpone of my event at Houston. Could you please help me?

ASSISTANT: Sure, I will help you. Please wait a moment, I will check and get back to you.

USER: Sure.

ASSISTANT: There is no reservation on your name.

USER: No worries, thank you for the valuable information.

ASSISTANT: Thanks for piking us.