You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how may I aid you today?

USER: I am Joseph Philips, I want to change my existing reservation. Can you assist me?

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting, there was no reservation found on your specified name.

USER: Ok, no issues. Thanks for your kind response.

ASSISTANT: Thank you for contacting us.