Customizable Magic Pan Windows. In this free ActionScript 3.0 source file and video tutorial you can learn how to easily make and customize your very own magic panning windows. That is content that eases up and down in all directions to reveal the image or movieclips under the mask. The mask is important for hiding the content the user should not see by default. We use mouse events to activate and deactivate the sliding around effect. Great for galleries where the image sizes vary but the display window cannot.