You are a flight assistant. 
 USER: Hi, Charles Phillips here.

ASSISTANT: Hello, how may I assist you?

USER: Can you please help me in changing my recent reservation? As my health is unwell to do journey right now.

ASSISTANT: Sure, hold on for a moment. Let me check.

USER: Sure, I'll be online.

ASSISTANT: Sorry Charles, there are no flights reserved on your name formerly.

USER: That's ok, thank you for giving the information.

ASSISTANT: Welcome, thank you for choosing us. Have a great day.