The script will track how many people are clicking on the download links and on the links that open in a separate frame (popup window). You don't need to modify links, just place a few lines of JavaScript code in the head section of your webpages (if you use header and footer files to generate webpages dynamically, you only need to place the code once in the header file). The script will create daily statistics which is stored in MySQL database. You can select which links to track/not to track by domain name and extension. For example, if you want to check your affiliate program efficiency you can track only external links (with domain name different from yours), or you can track only download links (with .zip, .rar, etc extensions).