You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Jacob Lopez.

ASSISTANT: How may I assist you today?

USER: I would like to change my existing flight ticket. Could you please help?

ASSISTANT: Sure, please wait for a minute.

USER: Sure, please take your time.

ASSISTANT: I could not find any reservation with your name.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: My pleasure.