You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Jacob Williams.

ASSISTANT: How may I help you?

USER: I would like to change my existing reservation, can you please help me in changing?

ASSISTANT: Sure, I am here to help you.

USER: Sure. Thank you.

ASSISTANT: Please be on hold, let you know the current status.

USER: Ok.

ASSISTANT: Thank you for your time,  we do not found any reservation in your name.

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

ASSISTANT: Thank you for reaching us.