Help.
I’m trying to build a registeration and login system, but I keep having this problem.
The data just doesn’t get received in the database!
Externally, the page doesn’t show me any error and functions like everything is alright.
I even tried putting a mysql_error() function after every query yet the page still doesn’t find anything wrong with it.
Please check my codes and try to find what’s wrong with them. 
controller/controller.php - pastebin.com/xCGuEKaa
model/model.php - pastebin.com/Qg8DF0f7
view/view_i.php - pastebin.com/FhPNjQGd
view/view_ii.php - pastebin.com/bLeGtiE7
sign_in.php - pastebin.com/CmK2FuUx