You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I want to change my existing reservation, can you please help me in this?

ASSISTANT: Sure, I can help you with that. May I know your good name please?

USER: Sure, my name is Jason Smith.

ASSISTANT: Ok, please wait for a while.

USER: Sure, I will wait.

ASSISTANT: Jason Smith, there is no active reservation found under your name to do changes in that.

USER: Ok, not an issue. Anyways, thank you for your service.

ASSISTANT: Thank you for choosing us.