You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how could I assist you at this moment?

USER: I would like to change my existing reservation. My name is Jerry Green.

ASSISTANT: Sure, I am here to help you. Please wait for few minutes, I will check with your existing reservation and give you an update.

USER: Ok.

ASSISTANT: Thank you for your time, there is no reservation find on Jerry Green in our data base.

USER: Thanks for the help.

ASSISTANT: Thank you for reaching us, have a great day ahead.

USER: Thanks.