Storing in a database is by far the most effective way to accomplish this. However if you are looking for a simple solution, try using a .htaccess file to password lock each file. Below is a simple example, change it to suit you exact needs.
AuthName "Name of Page"
Change: /path/to/htpasswd/file/.htpasswd to the full path to the .htpasswd file you have created with the login details.
Change "mypage.html" to the filename of the page you're protecting.
Hope that helps.