The MooTools slider is a good little application, and creates a reliable means of adding in a slider tool to a site. However, one thing that the MooTool slider is missing is a block that covers what is on the left hand side of the slider, before the handle.
Before we go into to how to create the tool, I have created an example of the slider. The colours are deliberately garish in order to show the different elements of the slider.
Create a page with the following HTML.