/**
* desc create shadow on element
*/
var SHADOW_OFFSET = 4;//default offset
var Z_INDEX =10;
function incZIndex()
{
    return ++Z_INDEX;
}


function shadowIt( _obj, _offset )
 {
      if(!_obj) return;
    _offset = _offset?_offset:SHADOW_OFFSET;
    var pos = GetPosition(_obj);
    var shadowStyle =  {
                        top     :pos.y+_offset+"px",
                        left    :pos.x+_offset+"px",
                        width   :pos.width+"px",
                        height  :pos.height+"px",
                        zIndex  :incZIndex()
                        };
    var shadowJSON = {
                        className:'jfcShadow',
                        id       :'___shadowId',
                        style    :shadowStyle
    };

    var alreadyShadow   = false;
    var container       = _obj.parentNode;
    var shadow          = 0;
      
    if (container.className=='jfcContainer')
    {
        var childNodes = container.childNodes;
        for(var i = 0; i < childNodes.length; i++)
        {
            if(childNodes[i].id=='___shadowId')
            {
                shadow = childNodes[i]; 
                break;
            }
        }
        ___prototype( shadow.style, shadowStyle );
    }
    else
    {
        var parentNode      = _obj.parentNode;
        parentNode.removeChild(_obj);
 
        container           = document.createElement('div');
        container.className = 'jfcContainer';
        shadow              = new dEl(container, 0, shadowJSON);
        container.appendChild(_obj);
        parentNode.appendChild(container);
    }
 }
 
 function removeShadow( _obj )
 {
    if(!_obj)return;
    if(_obj.parentNode.className=='jfcContainer')
    {
        var childNodes = container.childNodes;
        for(var i = 0; i < childNodes.length; i++)
        {
            if(childNodes[i].id=='___shadowId')
            {
                shadow = childNodes[i]; 
                break;
            }
        }
    }
    _obj.parentNode.removeChild(shadow);
    //@TODO recombine objects
 }
 
 /**
 * shadow as child of object
 */
 function _shadowIt( _obj )
 {
    var shadow = new dEl(_obj,0,{className:'jfcShadow'})
    shadow.prototype.style.top = "300px";
 }