You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: Can you help me to change the reservation which I had done a week ago?

ASSISTANT: I will help you please share your name please?

USER: Ok, my name is Daniel Anderson.

ASSISTANT: No reservation found in our database as per your preferences.

USER: Ok, thank you for assisting me.

ASSISTANT: Thank you for choosing us.

USER: May be my friend had changed my reservation. Anyways, thank you for assisting me.

ASSISTANT: My pleasure to serve you.