If you simply want to open a complete gallery in a lightbox-style pop-up/overlay (rather than open an image via the showOpenButton option) as 'john givens' has done above with AutoViewer, then this can be easily achieved by using a script such as Shadowbox.
(1) Download Shadowbox and unzip the package into the same directory as your main HTML page.
(2) Copy the following code into the <head> section of your main HTML page.
<link rel="stylesheet" type="text/css" href="shadowbox.css">
(3) Create a SimpleViewer gallery (for example using svBuilder) and upload the complete gallery folder (not just the contents) to your web server.
(4) Link to the gallery's HTML index page using the rel="shadowbox" attribute, eg.
<a href="gallery_folder/index.html" rel="shadowbox">Click here to open the gallery using Shadowbox.</a>
SimpleViewer Support Team