You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: My name is Rachel Hernandez and I would like to change an existing reservation.

ASSISTANT: Sure, please wait while I check your recent reservation.

USER: Sure, take your time.

ASSISTANT: We found no reservation on your name.

USER: No problem, thank you for the help.

ASSISTANT: Thank you for contacting us.