An image map is a graphic that is displayed in an HTML page that allows limited user interaction. When you click in an imagemap, the x/y coordinates of the click are appended to a GET request that is sent to the server. The server can then use the coordinates to perform some additional processing, such as zooming in on a region surrounding the selected point.

When an HTML browser downloads an image with ISMAP appended to its URL, that image is interpreted to be an image map. When a user clicks in an image map, the resulting GET request contains the x/y coordinates of the click in its URL. On the server, the servlet that handles the GET request must include code that handles the image map coordinates. In the JWaveJSPServlet, for example, the doGet method tests for the presence of appended x/y coordinates, strips off the x and y values, and stores them along with other parameters and passes them to a JWAVE wrapper function that is executed by PV‑WAVE. It is up to the developer to determine what the wrapper function actually does with the image map coordinates that are passed to it.

If you want an image that is returned from PV‑WAVE to the JWaveJSPServlet (or a custom servlet that you write) to be an image map, set the Ismap keyword in the PACKIMAGE wrapper function. The PACKIMAGE function is described in the next section.