You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Sarah Brown.

ASSISTANT: How may I lend a hand to?

USER: Can you please help me in changing my existing reservation? As my meeting got postponed at Houston.

ASSISTANT: Sarah Brown, I am willing to help you for this. Let me check your reservation status?

USER: Sure, I will wait for your information.

ASSISTANT: Sorry to inform that, no reservation is found with your criteria.

USER: Ok, not an issue. Thank you for providing information.

ASSISTANT: Thank you very much for approaching our agency.