JavaScript and XHTML

JavaScript is most commonly embedded within an XHTML Web page to provide additional features which are not available simply through using XHTML alone. For JavaScript-enhanced Web pages to behave correctly, the browser used to view it must have a JavaScript interpreter. There are still some die-hards who are not using JavaScript enabled versions of these browsers, but since browsers can be downloaded free, the vast majority of users can be assumed to have browsers which will interpret the latest versions of JavaScript correctly. A more serious problem is that the JavaScript interpreters in the two leading browsers from Netscape and Microsoft either do not understand all of the features of JavaScript or interpret them in different ways. JavaScript and the browsers are constantly evolving and if you are developing applications using JavaScript it is advisable to check that the final version works with a variety of popular browsers. The picture is further complicated by other scripting languages such as Microsoft’s JScript which is very similar to JavaScript.