How can I resize a DIV by dragging just ONE side of it?

Been looking to do this, very nice solution by Gaby. Although my requirement was not to have any absolute elements and use percentages instead of pixels, so I've changed Gaby's code a little to cater for this (if anyone is interested)

CSS

#main{
  background-color: BurlyWood;
  float: right;
  height:200px;
  width: 75%;
}
#sidebar{
  background-color: IndianRed;
  width:25%;
  float: left;
  height:200px;
  overflow-y: hidden;
}
#dragbar{
  background-color:black;
  height:100%;
  float: right;
  width: 3px;
  cursor: col-resize;
}
#ghostbar{
  width:3px;
  background-color:#000;
  opacity:0.5;
  position:absolute;
  cursor: col-resize;
  z-index:999
}

JS

var i = 0;
var dragging = false;
$('#dragbar').mousedown(function(e){
   e.preventDefault();

   dragging = true;
   var main = $('#main');
   var ghostbar = $('<div>',
                    {id:'ghostbar',
                     css: {
                            height: main.outerHeight(),
                            top: main.offset().top,
                            left: main.offset().left
                           }
                    }).appendTo('body');

    $(document).mousemove(function(e){
      ghostbar.css("left",e.pageX+2);
   });

});

$(document).mouseup(function(e){
   if (dragging) 
   {
       var percentage = (e.pageX / window.innerWidth) * 100;
       var mainPercentage = 100-percentage;

       $('#console').text("side:" + percentage + " main:" + mainPercentage);

       $('#sidebar').css("width",percentage + "%");
       $('#main').css("width",mainPercentage + "%");
       $('#ghostbar').remove();
       $(document).unbind('mousemove');
       dragging = false;
   }
});

Demo: http://jsfiddle.net/Bek9L/3020/

Have a look at this example

Html

<div id="sidebar">
     <span id="position"></span>
    <div id="dragbar"></div>
    sidebar
</div>
<div id="main">
    main
</div>

jquery

var dragging = false;
$('#dragbar').mousedown(function(e){
   e.preventDefault();

   dragging = true;
   var main = $('#main');
   var ghostbar = $('<div>',
                    {id:'ghostbar',
                     css: {
                            height: main.outerHeight(),
                            top: main.offset().top,
                            left: main.offset().left
                           }
                    }).appendTo('body');

    $(document).mousemove(function(e){
      ghostbar.css("left",e.pageX+2);
   });
});

$(document).mouseup(function(e){
   if (dragging) 
   {
       $('#sidebar').css("width",e.pageX+2);
       $('#main').css("left",e.pageX+2);
       $('#ghostbar').remove();
       $(document).unbind('mousemove');
       dragging = false;
   }
 });

Demo at http://jsfiddle.net/gaby/Bek9L/1779/

it is an alteration from the code i posted in Emulating frame-resize behavior with divs using jQuery without using jQuery UI?