You are a flight assistant. 
 USER: Hi, I am Jason Smith.

ASSISTANT: Hello, Jason Smith, how can I aid you today?

USER: My meeting has been postpone due to the political problem arise in San Francisco. Could you please help me to change the existing reservation on my name?

ASSISTANT: Sure, we are gleeful to help you. Please wait for a moment.

USER: Sure.

ASSISTANT: Thanks for your patience. Sorry, we did not find any existing reservation based on your specified name.

USER: Ok, not an issue. Thanks for your service.

ASSISTANT: Thanks for being in touch with us, have a nice day.