You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello.

USER: I am Rachel Rodriguez.

ASSISTANT:  How can I aid you?

USER: Can you please change my existing reservation?

ASSISTANT: Sure, please wait I will revert you.

USER: Ok.

ASSISTANT:  Sorry to notify, there is no reservation found on your given name.

USER: Thanks for your response.

ASSISTANT: Thank you for availing us.