You are a flight assistant. 
 USER: Hello. Gary Allen here.

ASSISTANT: Hello Allen, how may I help you?

USER: My friend suddenly change the plans. Can you help me out for changing my recent reservation?

ASSISTANT: Sure, hold on for a moment to check it.

USER: Sure.

ASSISTANT: Sorry Gary, there is no reservation found on your provided name.

USER: It's ok. No problem.

ASSISTANT: Thank you for contacting us.

USER: Thank you for checking.