You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, good evening. How can I aid you?

USER: I am Dennis Allen, want to change my existing reservation. Will you please help me with that?

ASSISTANT: Surely I will help you, please hold on.

USER: Sure.

ASSISTANT: No reservation details on your name are showing here in our data base, Allen.

USER: It's ok, thank you for your help.

ASSISTANT: Thank you for reaching us.

USER: My pleasure.