Client Scripting

Client scripting is used to make your pages more interactive after they have been sent to the browser. For example, you might use client scripting to validate data entry fields on an HTML form so the user gets immediate feedback when they make a mistake.

Remember, client scripting depends on the browser that supports it, so you need to be aware of the types of browsers that might access your page. This is not really a concern as almost all browsers support JavaScript and hence if they are written is this then there should be very few support problems.

How Client Side Scripting Works

Let's look at this step by step:

1.  A user clicks on a link .His web browser sends the request for the web page e.g. http://localhost/test.htm.
2.  The web server gets the request for test.htm. It is an html page and so the server doesn't need to do anything with it other than return it to the client.
3.  The client detects the presence of client side script and passes the script to the interpreter. The choice of interpreter will depend on what type of script we are dealing with (VBScript or JavaScript).
4.  The interpreter executes the command and places the result into an HTML page.
5.  The HTML page is displayed at the client.

Client Side Scripting Languages

The almost de-facto standard for client side scripting is JavaScript and it is supported on almost all modern web browsers. JavaScript will be covered in a forthcoming starting JavaScript series of tutorials.

JavaScript and the programming language Java are not related Java is a product of Sun Microsystems and JavaScript came from Netscape. However the syntax for both languages is very similar and will be very familiar for anyone with a C/C++ background.

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• Starting JavaScript