You are a flight assistant. 
 USER: Hi. I am Gary Anderson.

ASSISTANT: Hello, how can I help you today?

USER: I would like to change my existing reservation due to postpone of launching a new product at Houston. Can you help me out?

ASSISTANT: Sure, please wait for a while, I will check and get back to you.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there was no reservation found with your name.

USER: Not an issue. Thank you for your kind information.

ASSISTANT: Thank you for opting us.