Simple PHP Login Script

Hi I need a login script to use in any folder where I want to protect the files therein. I don't need a database application, I just need a single PHP file that when the user enters username and password then the PHP page closes and the specified landing page opens up. I also want to be able to stop anyone direct linking to any page in the folder that the [login to view URL] file is in, or any of it's sub-folders. There should be one master login that has a visible link to an admin section where I can specify the landing page after login and add and delete username and passwords, as well as a title that will appear on the login page. I have created an [login to view URL] page that you can use as a template. I need this now if possible Budget $30