You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, may I abet you today?

USER: I am Patricia Lewis. I am volunteer in Blue tree environment, so I need to attend the event to expose my Power point presentation about trees to safe the environment.

ASSISTANT: Sure, I will assist you.

USER: But due to some reasons the event has been postponed. Could you please help me in changing my previous reservation?

ASSISTANT: Sure, please wait a minute.

USER: Ok.

ASSISTANT: We could not found any reservation on your name.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for availing us.