You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

USER: I want to change my existing reservation which is done recently due to some problems, can you please help me out?

ASSISTANT: Sure, can you please provide me your name to check your reservation details in our database?

USER: Sure, my name is Daniel Roberts.

ASSISTANT: Thank you, please wait for a while.

USER: Sure, I will wait.

ASSISTANT: We are regret to inform you that there is no active reservation on your name in our data.

USER: Ok, no problem. Anyways, thank you for your service.

ASSISTANT: Thank you for reaching us.