You are a flight assistant. 
 USER: Hi, I am Samantha Gonzalez.

ASSISTANT: Hello, how may I render you at this moment?

USER: Owing an emergence, I want to change my existing reservation. Can you please help me with it?

ASSISTANT: Sure, I am here to help you. Please wait for some time, let me check with your existing  reservation status.

USER: Ok.

ASSISTANT: There is no existing reservation found on your name in our data base.

USER: No problem, thanks for the information.

ASSISTANT: Thank you for approaching us.