JK Pop-up image viewer

Use this feature-rich image viewer script to allow your visitors to selectively choose an image to view, by clicking on a link. The image is launched in a separate, fit window. Supports a text description, displayed beneath the image. Ability to set a background color/image for the pop up window. Only one pop up window open at all times to avoid agitation. For example, if the user clicks on multiple links to view multiple images, the same pop up window is used, instead of spawning a new one for each image. Pop up window is centered on page the first time it's activated. Subsequent calls to it are not, so the user may choose to drag the window to a custom location if desired.