Compatibility Issues

You should note that the capabilities of browsers are increasing with each version, and while a page you develop with all the Java bells and whistles, it may not on a machine running a lower version of the same browser, or a different browser. You should always attempt to test your pages on both the major browsers (Netscape Navigator and Microsoft Internet Explorer), using both older and more recent versions. If possible, you should also try it on smaller browsers such as Opera. If the form does not work as designed, the page should offer some alternative rather than forcing users to get the same browser as you.

If you do develop some code which only runs on a specific browser or version or browser, provided it does not matter whether the code runs or not you can check that the user has this browser before running the code. If you try to run the code on a different browser you may get very ugly error messages, while if you check the browser version first it will look much more professional. This is achieved by placing the following code around the problem code:

if(navigator.appName == 'Microsoft Internet Explorer' && navigator.appVersion >= '4')
   {
   Place your code here
   };

This code will check whether the user has Microsoft Internet Explorer version 4 or higher before running you code. You can modify this code to suit your own needs.