Really quick and simple code in order to show or hide a layer on your webpage using Javascript. This can be used as the basis for things such image galleries, video popups and if you have no soul then it can be used for web advertising
Effectively what we do is define a layer in CSS and then write a couple of functions, one to set the visibility and position of the layer and the other to find the position on the page that it should appear. You can then add whatever you want inside the layer ready to be shown or hidden when a user clicks a link, or anyother way to activate the function.
Quick popup/overlay show and hide a layer with Javascript and CSS
