Since I wanted some of the things to not be changed I set the input of them as disabled.
The thing is, as it's disabled, the PHP doesn't recognize it's variable.
form doesn't submit the disabled input controls. However you may use readonly
attribute, if it suits for your needs.
In fact, there is nothing hidden/readonly when it comes in the client side. Users can easily manipulate the client side source code. So, you must always validate all external data, before using them at server side.