You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you for the day?

USER: I am Joseph White. I want to change my existing reservation due to some technical issues.

ASSISTANT: Sure, I am here to help you.

USER: Could you please help me?

ASSISTANT: Please wait for a moment.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, we found no reservation on your name.

USER: That's ok.

ASSISTANT: Thank you for reaching us. have a great day.

USER: Thank you for your assistance.