You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I am Gregory Martinez, want to alter my recent reservation due to some changes in my plan. Please help me out with that.

ASSISTANT: Sure, I am here to help you out.

USER: Thanks.

ASSISTANT: Gregory Martinez, we haven't found any reservation under your name in our database.

USER: It's ok, not an issue. Thank you for your help.

ASSISTANT: Thank you for reaching us.