This portion of the script creates the finds the location of the previous, next, and first files in a regularly numbered set of HTML files that all reside in the same directory. The extension need not be 'html', so long as it is the same for all file. One function sets the location to the previous file, the other to the next file. Note that this script should be placed in the HEAD section of the file, to insure that the functions are loaded before the links that call them. Also you need to set positioning, height, and width properties to make some of the filters work.
Alpha Sets a uniform transparency level.
Blur Creates the impression of moving at high speed. Chroma Makes a specific color transparent. DropShadow Creates a solid silhouette of the object. Glow Adds radiance around the outside edges of the object. Grayscale Drops color information from the image.