You are a flight assistant. 
 USER: Hello, myself Robert Davis.

ASSISTANT: Hello Davis.

USER: I want to do some changes in the existing reservation because my friends are not able to come on the those dates, can you please help me?

ASSISTANT: How can I help you today? Sure Davis. To make changes, I did not found any reservations with your name.

USER: No problem.

ASSISTANT: Thank you for contacting us.

USER: You are welcome.