You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself George Lopez.

ASSISTANT: How can I assist you?

USER: Due to some issues, I want to change my existing reservation. Can you please help me to change my reservation?

ASSISTANT: Sure, I will help you with this.

USER: Ok.

ASSISTANT: There is no active reservation found with your name in our database.

USER: Thank you very much for your information.

ASSISTANT: Thank you for reaching us.