I haven't went through the code of this one yet but I know the script it is based on. I made my own version of this as well because the original version is insecure. I hope you've secured this one!
In this project, main drawback is any masters can also delete the Admin or the Super User. So accessing of Admin profile by masters or agents should not be encouraged.
This system looks easy but has functions in it that have been deprecated in PHP5 Deprecated: Function eregi() is deprecated in C:\wamp\www\GISdataadmin.uvi.edu\login\userinfo.php on line 22 Need to update this to something more recent. Also would be nice to have a set of directions as a read me in the folder.