You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how can I help you today?

USER: I am Margaret Thomas. Can you please help me in changing my existing reservation?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry to inform, no reservation found with your name.

USER: Thanks for your response.

ASSISTANT: Thanks for reaching us.