The Ethics and Access of Login

list, I have been using .htaccess pages formatted to read username/password from a mysql database, and they work fine. But I'm wondering, wouldn't it be simpler to simply write a script that checks a database itself, and, if it finds the username, goes on to the next action; and if it doesn't find the member, shuts them out? This seems so simple that I am sure there are good arguments against it. Am I right? The idea, in simple terms, is a login form that calls a php script which checks the id of the username in the form against a database, and then the appropriate action following their acceptance. thanks, Sarah