how to create a moving tab slide content in this tutorial. Basically, the tab section simulate Lava Lamp Effect, and the content is using animate method to slide it.

1. HTML

In the container #moving_tab, we have two sections in the HTML code - tabs class and content class. Tabs class contains 2 tabs, and content class contains 2 ul lists.

<div id="moving_tab">
 <div class="tabs">
  <div class="lava"></div>
  <span class="item">Tab 01</span>
  <span class="item">Tab 02</span>

 </div>
     
 <div class="content">      
  <div class="panel">      
   <ul>
    <li><a href='#'>Panel 01 Item 01</a></li>
    <li><a href='#'>Panel 01 Item 02</a></li>
    <li><a href='#'>Panel 01 Item 03</a></li>
    <li><a href='#'>Panel 01 Item 04</a></li>
    <li><a href='#'>Panel 01 Item 05</a></li>
   </ul>
   <ul>
    <li><a href='#'>Panel 02 Item 01</a></li>
    <li><a href='#'>Panel 02 Item 02</a></li>
    <li><a href='#'>Panel 02 Item 03</a></li>
    <li><a href='#'>Panel 02 Item 04</a></li>
    <li><a href='#'>Panel 02 Item 05</a></li>   
   </ul>      
  </div>

 </div> 
</div>

2. CSS

I have put comment in every important css style. Bear in mind that, if you change the width of #moving_tab, you might have to change the width value in .item, .lava, .panel, ul.

 body {
  font-family:arial;
  font-size:12px; 
 }
 
 a {
  color:#333;
  text-decoration:none;
  display:block;
 }

 a:hover {
  color:#888;
  text-decoration:none;
 }
 
 #moving_tab {
  /* hide overlength child elements*/
  overflow:hidden;
  
  /* all the child elements are refering to this width */
  width:300px;

  /* fix ie 6 overflow bug */
  position:relative
  
  /* styling */
  border:1px solid #ccc; 
  margin:0 auto;
 }
 
  #moving_tab .tabs {
   /* enable absolute position for .lava */
   position:relative; 
   height:30px;
   
   /* styling */
   padding-top:5px;
   cursor:default;
  }
 
  #moving_tab .tabs .item {
   /* enable z-index */
   position:relative;
   z-index:10;
  
   /* display in one row */
   float:left;
   display:block;

   /* width = half size of #moving_tab */
   width:150px;
   
   /* height = height of .tabs */
   text-align:center;
   font-size:14px;
   font-weight:700; 
  }

  #moving_tab .tabs .lava {
   /* Set it to absolute */
   position:absolute;
   top:0; left:0;
   
   /* display the lava in bottom most layer */
   z-index:0;  
    
   /* width = half size of #moving_tab */
   width:150px;

   /* height = height of .tabs */
   height:30px;
   
   /* styling */
   background:#abe3eb;

  }
  
  #moving_tab .content {
   /* enable absolute position for .panel */ 
   position:relative;
   overflow:hidden;
   
   /* styling */
   background:#abe3eb;
   border-top:1px solid #d9fafa;
  }
  
  #moving_tab .panel {
   /* width is width of #moving_tab times 2 */
   position:relative;
   width:600px;
  }
  
  #moving_tab .panel ul {
   /* display in one row */
   float:left;
   
   /* width is the same with #moving_tab */
   width:300px;
   
   /* remove all styles */
   padding:0;
   margin:0;
   list-style:none;
   

  }
   /* styling */
   #moving_tab .panel ul li {
    padding:5px 0 5px 10px; 
    border-bottom:1px dotted #fff;
   }

3. Javascript

I learnt new trick in jQuery scripting - position() method. I have been using offset() method to calculate the position of elements, it's really hassle because the position:relative of elements can influence the value of offset.

This is the code I used to use:

• $('#moving_tab').offset().left - $(this).offset().left + $(this).width()

and it can be replaced by:

• $(this).position()['left']

Don't know why I couldn't find this method. But hey! it's something new and I'm excited. Anyway, the jQuery script is quite simple, we only have to animate lava class and panel.

 
$(document).ready(function () {

 //set the default location (fix ie 6 issue)
 $('.lava').css({left:$('span.item:first').position()['left']});
 
 $('.item').mouseover(function () {
 
  //scroll the lava to current item position
  $('.lava').stop().animate({left:$(this).position()['left']}, {duration:200});
   
  //scroll the panel to the correct content
  $('.panel').stop().animate({left:$(this).position()['left'] * (-2)}, {duration:200});
 });
  
});