Client Side Scripts

Client side scripts are scripts the browser runs on the visitor's computer. There is no communication between the web server and the browser. All the script processing is done via the browser.

Client side scripts are coded directly into the HTML document or in an external file.

Client side scripts can be used to check the validity of information within forms before submitting, to write information to the web page such as the current date and time, to perform certain things when activated by the visitor such as showing and hiding page items. For more information on client side scripting and HTML visit http://www.w3.org/TR/WD-script-970314

Newer browser security features enable the visitor to disable scripting. This could be a problem if the web page relies on client side scripting to convey information such as naviagtion (e.g. cascading menus, expanding menus).

Search engines do not read scripts therefore if the navigation system on the page is not viewable without executing the script the search engine spiders will not follow the links to other pages.

Some commonly used client side scripting include:

JavaScript

Javascript was developed by Netscape and is executable in all browsers.

Please note:  Javascript and Java are not the same thing. They are completely differnt programming techniques. Javascript is compiled and executed by the browser, Java is compiled into something called Applets and inserted into the web page.

VBScript

VBScript is Mircrosoft's version of javascript. It can be inserted into a web page or used as part of an ASP page. It is proprietary coding that only works if the visitor is using Internet Explorer when inserted directly into the web page. If inserted into an ASP page script as part of the creation of the page before it is sent back to the browser then the type of browser the user is using shouldn't be a problem.

Java Applets

Java applets are small programs imbedded into the web page which are run by the browser. They are quite secure as they cannot access the user's computer and generally do not send information out to other computers.

Java applets are used for things like animation, clocks, calculator, etc.

DHTML - Dynamic HTML

DHTML uses scripts to dynamically change the content of the web page via the browser.

Some examples of DHTML would include cascading menus, items that appear and/or disappear depending on the visitors actions, sorting or filtering information received from the web server without requesting the information again from the server.