You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: Can you please help me to change my existing reservation?

ASSISTANT:  Sure, I can change your reservation right now. Before that I need to know your good name please?

USER: Thank you for your response, I am Debra Lee.

ASSISTANT: We regret to inform you that there is no active reservation found on your name.

USER: It's ok not a problem, thank you for checking.

ASSISTANT: Thank you for opting us.