You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: My name is Debra Martinez.

ASSISTANT: Glad to meet you Debra Martinez.

USER: Please modify my reservation which my friend had done recently.

ASSISTANT: Sure, I am here to help you. Hold on for a moment. Let me check.

USER: Ok, I will wait for you.

ASSISTANT: Sorry Debra Martinez, there are no flights reserved on your given dates formerly.

USER: Ok, thank you for assisting me.

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