Pure JavaScript Draggable

http://www.dte.web.id

HTML

<div id="draggable-element">Drag me!</div>

CSS

body {padding:50px;transform-origin:top left;transform:scale(0.5);}

#draggable-element {
  width:100px;
  height:100px;
top:0;
    left:0;
  background-color:#666;
  color:white;
    margin:-50px;
  padding:10px 12px;
  cursor:move;
  position:relative; /* important (all position that's not `static`) */

}

JavaScript

var selected = null, // Object of the element to be moved
    x_pos = 0, y_pos = 0, // Stores x & y coordinates of the mouse pointer
    x_elem = 0, y_elem = 0; // Stores top, left values (edge) of the element

// Will be called when user starts dragging an element
function _drag_init(elem, a, d) {
    // Store the object of the element which needs to be moved
    selected = elem;
    x_elem = x_pos / a - selected.offsetLeft;
    y_elem = y_pos / d - selected.offsetTop;
}

// Will be called when user dragging an element
function _move_elem(e) {
var el = window.document.body;
var st = window.getComputedStyle(el, null);
var tr = st.getPropertyValue("transform") ;

var values = tr.split('(')[1];
    values = values.split(')')[0];
    values = values.split(',');

var a = values[0];
var b = values[1];
var c = values[2];
var d = values[3];
    x_pos = document.all ? window.event.clientX : e.pageX;
    y_pos = document.all ? window.event.clientY : e.pageY;
    if (selected !== null) {
        selected.style.left = ((x_pos / a) - x_elem) + 'px';
        selected.style.top = ((y_pos /  d) - y_elem) + 'px';
    }
}

// Destroy the object when we are done
function _destroy() {
    selected = null;
}

// Bind the functions...
document.getElementById('draggable-element').onmousedown = function () {
    var el = window.document.body;
var st = window.getComputedStyle(el, null);
var tr = st.getPropertyValue("transform") ;

var values = tr.split('(')[1];
    values = values.split(')')[0];
    values = values.split(',');

var a = values[0];
var b = values[1];
var c = values[2];
var d = values[3];
    _drag_init(this,a,d);
    return false;
};

document.onmousemove = _move_elem;
document.onmouseup = _destroy;