You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how could I assist you today?

USER:  I am Charles Rodriguez want to change my reservation owing an emergency. Can you help me in changing?

ASSISTANT: Sure, please wait for a while let me check and get back to you.

USER:  Ok.

ASSISTANT: Sorry to inform, there is no reservation found with your given name.

USER:  Thank you for your help.

ASSISTANT: Thank you for reaching us.