New inputs

Hello everyone.
I am working on 4-full-mvc and I wanna ask u something.
I need one or more inputs like name,surname. I already add these inputs on my registration page but when I tried everytime to register I am always getting undefined variables in line 535 on model/login_model.php file. (line 535 in my file which means INSERT INTO line.) 
What am I suppose to do?
Thank you.