You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Steven Lee.

ASSISTANT: How can I help you Steven Lee?

USER: I want to make some changes in existing reservation because I have planned to stay for some more days with my mother in Philadelphia. Can you please help me?

ASSISTANT: Give me a moment, let me check your reservation status in our database.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found with the name of Steven Lee in our database.

USER: That's fine, not an issue. Thank you for your information.

ASSISTANT: Thank you for utilising our services.