You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: Due to some franchise meeting, I am going to change my reservation. Can you please help me for this?

ASSISTANT: Sure, I am here to help you.

USER: Thank you very much for quick access.

ASSISTANT: Can you share your name to check further?

USER: Myself David Parker.

ASSISTANT: Please stand by.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, I regret to inform you that no reservation was found on your name in our portal.

USER: Not a big deal, anyhow thank you very much for your service.

ASSISTANT: Thank you for contacting us.