Jscalender module come with Jstools package in drupal 5 you can
download drupal jstools package from the drupal.org site.Jscalender
uses the jsCalendar javascript library, like using a special CSS class
called via #attribute in the form element array to convert textfields
into jcalendar enabled.



The jcalendar module uses hook_form_alter() to look for textfields with
the add-jcalendar class, I had to use something different than
jcalendar which is used later on the generated form elements by the
jQuery code.

Jquery is lightweight Java Script Library that provides functionality for may events in just few lines of code.To use jquery you must download first the jquery library file.

 You can download the latest version -- 1.2.6 the latest version from jquery site.

Functionality And Working Of Jquery :-

Jquery sees sets of HTML nodes as objects to pass messages to (more like the traditional Ruby way). So instead of having a separate class that adds text after an HTML node, jQuery glues the functionality onto the jQuery object, which is returned by the $ function. By contrast, Prototype’s $ function returns a vanilla DOM node. In Prototype effects you can inherit your effect from some base effect and this have some nice features like configurable 'easing' function, which can control effect speed over time, or some other stuff for free.

"jQuery is a fast and concise JavaScript Library that simplifies HTML document traversing, event handling, animating, and Ajax interactions for rapid web development. jQuery is designed to change the way that you write JavaScript.A lightweight framework that easily handles tedious DOM scripting chores."

Some quick feature of Jquery Are:-

* Lightweight Footprint
About 15KB in size (Minified and Gzipped).Very small size and so takes very little amount of time to load in memory.

* CSS3 Compliant
Supports CSS 1-3 and basic XPath syntax and rules.

In drupal if we want to get tabs we can use different type of modules for it.One of them is quick tabs but it makes little slower performance on server side.In this case we will be getting all data for all tabs togather and based on click event tabs will be shown or hidden.

Another on is magic_tab module in drupal.It provide better way for creating tabs in drupal.All things which you will need is to customize the module looks and feels.you also muct have idea of custom module in drupal and how to create php functions.

Here is a default example that was provided with magic_tab module.It makes dynamic requests to server based on tab selection.