How to have hidden link actions on PNG image?

http://www.ika-world.com/search.p开发者_JS百科hp?view=weltkarte

See link for example.

Image is a PHP created PNG image. When viewing just the image, then no link actions are present. I cant figure out how the link actions are added. Please help.

There is no imagemap on the page, I believe that the page is using javascript to set up a click listener. It then gets the X/Y position of the click and changes the URL with the new parameters. The javascript is compacted so i cannot tell you exactly how to replicate it, but that is how he is doing it.

One way to do it is with image maps.