Not exactly the most used script, but this one allows you to reference the page name in a variable. Instead of yourdomain.com/index.html, you can use this script to create a variable that stores index.html for your use! You can use it with alerts, document.write, etc. Take a look!
The JavaScript Source: Page Details: Page Variable
Simply click inside the window below, use your cursor to highlight the script, and copy (type Control-c or Apple-c) the script into a new file in your text editor (such as NotePad or SimpleText) and save (Control-s or Apple-s). The script is yours!
Page Details