Images

HTML forms support an INPUT type of image that functions like a submit button. When clicked, the data of all fields is submitted to the action URL of the FORM tag.

Three pieces of information are sent from the image field: first the name of the image, but more usefully the x and y coordinates of the point on which the picture was clicked. With the "point of click" data, you can customize the return to be specific to just one portion of the picture. These areas are referred to as hotspots. There are automated ways to divide up the hotspots on a picture, but to do it yourself you have to do some experimenting with the RequestSniffer, to feel out the boundaries of the hotspots.

Note that you will get new x and y coordinates if you make any changes to an image, including:

• Resizing
• Changes made to the graphic itself in the graphic editor
• Recropping

However, you can move the image to a new location on the page without affecting the hotspots. And, to answer a frequent question, you don't have to use the hotspots to subdivide an image. If the user clicks an image on the form you can just use the name of the image in your response, without using the point of click data.