You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Due to personal issues, I would like to change my existing reservation to some other dates. Can you help me?

ASSISTANT: Sure, I will help you. Please help me with your name.

USER: My name is David Perez.

ASSISTANT: David, no reservation has been found on your name in our database.

USER: Its ok, no issues. Thank you for the information.

ASSISTANT: Thank you for approaching us.