How To Make An Imagemap

Chapter 1: Server-Side Imagemaps

• You place some code in your HTML pages and the image is displayed.
  
  
• When the user clicks on the image, the X and Y coordinates of the click, relative to the top left of the image, are sent back to the web server.
  
  
• The web server then needs to figure out how to respond.

1. Either, you can make clicks on the image link to your own ASP, CGI, PHP script, and then develop your own script which responds in whichever way you want.
   
   
2. Or, on some web hosts, it is possible to setup a text file specifying the coordinates of various regions on the image, and what happens when any particular region is clicked.
   
   Just to make this more confusing there are at least two different formats that this text file can be in, depending on your web host: NCSA and CERN. Check with your web host to see which, if any, of these formats they support.

• Every click on the image generates a separate request to the server.
  
  
• The procedures for Server-Side imagemaps involve either writing your own scripts (too much work!), or depend on which particular web host you are currently using (and thus might need to be changed if you switch to another web host).
  
  
• It is not possible to provide the user with any visual cues when they are moving their mouse over the imagemap. Instead, all they see is the status line of the browser contains the URL of the script with the X and Y coordinates as parameters. You can see what I mean by this, by looking at the imagemap below, and moving your mouse over it.

Server-Side Imagemap
(Not Functional)

• The first part in red is the URL of the script on the server to link to.
  
  
• The ISMAP attribute tells the browser, that the linked image should be treated as a Server-Side imagemap, and that the X,Y coordinates should be sent to the server when the user clicks.