function calculateSize(returnwidth) {

  var myWidth = 0, myHeight = 0;

  if( typeof( window.innerWidth ) == 'number' ) {

    //Non-IE

    myWidth = window.innerWidth;

    myHeight = window.innerHeight;

  } else if( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) {

    //IE 6+ in 'standards compliant mode'

    myWidth = document.documentElement.clientWidth;

    myHeight = document.documentElement.clientHeight;

  } else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) {

    //IE 4 compatible

    myWidth = document.body.clientWidth;

    myHeight = document.body.clientHeight;

  }

  if (returnwidth) return myWidth;

  else return myHeight;

}

var counter = 90;

var Drag = {



  obj : null,



  init : function(o, oRoot, minX, maxX, minY, maxY, bSwapHorzRef, bSwapVertRef, fXMapper, fYMapper)

  {

    o.onmousedown  = Drag.start;



    o.hmode      = bSwapHorzRef ? false : true ;

    o.vmode      = bSwapVertRef ? false : true ;



    o.root = oRoot && oRoot != null ? oRoot : o ;



    if (o.hmode  && isNaN(parseInt(o.root.style.left  ))) o.root.style.left   = calculateSize(true)/2 + 'px';

    if (o.vmode  && isNaN(parseInt(o.root.style.top   ))) o.root.style.top    = '140px';

    if (!o.hmode && isNaN(parseInt(o.root.style.right ))) o.root.style.right  = "0px";

    if (!o.vmode && isNaN(parseInt(o.root.style.bottom))) o.root.style.bottom = "0px";



    o.minX  = typeof minX != 'undefined' ? minX : null;

    o.minY  = typeof minY != 'undefined' ? minY : null;

    o.maxX  = typeof maxX != 'undefined' ? maxX : null;

    o.maxY  = typeof maxY != 'undefined' ? maxY : null;



    o.xMapper = fXMapper ? fXMapper : null;

    o.yMapper = fYMapper ? fYMapper : null;



    o.root.onDragStart  = new Function();

    o.root.onDragEnd  = new Function();

    o.root.onDrag    = new Function();

  },



  start : function(e)

  {
	
    var o = Drag.obj = this;

	//alert (counter);
	counter++;
	o.root.style.zIndex = counter;	
		
	
	
    e = Drag.fixE(e);

    var y = parseInt(o.vmode ? o.root.style.top  : o.root.style.bottom);

    var x = parseInt(o.hmode ? o.root.style.left : o.root.style.right );

    o.root.onDragStart(x, y);



    o.lastMouseX  = e.clientX;

    o.lastMouseY  = e.clientY;



    if (o.hmode) {

      if (o.minX != null)  o.minMouseX  = e.clientX - x + o.minX;

      if (o.maxX != null)  o.maxMouseX  = o.minMouseX + o.maxX - o.minX;

    } else {

      if (o.minX != null) o.maxMouseX = -o.minX + e.clientX + x;

      if (o.maxX != null) o.minMouseX = -o.maxX + e.clientX + x;

    }



    if (o.vmode) {

      if (o.minY != null)  o.minMouseY  = e.clientY - y + o.minY;

      if (o.maxY != null)  o.maxMouseY  = o.minMouseY + o.maxY - o.minY;

    } else {

      if (o.minY != null) o.maxMouseY = -o.minY + e.clientY + y;

      if (o.maxY != null) o.minMouseY = -o.maxY + e.clientY + y;

    }



    document.onmousemove  = Drag.drag;

    document.onmouseup    = Drag.end;



    return false;

  },



  drag : function(e)

  {

    e = Drag.fixE(e);

    var o = Drag.obj;



    var ey  = e.clientY;

    var ex  = e.clientX;

    var y = parseInt(o.vmode ? o.root.style.top  : o.root.style.bottom);

    var x = parseInt(o.hmode ? o.root.style.left : o.root.style.right );

    var nx, ny;



    if (o.minX != null) ex = o.hmode ? Math.max(ex, o.minMouseX) : Math.min(ex, o.maxMouseX);

    if (o.maxX != null) ex = o.hmode ? Math.min(ex, o.maxMouseX) : Math.max(ex, o.minMouseX);

    if (o.minY != null) ey = o.vmode ? Math.max(ey, o.minMouseY) : Math.min(ey, o.maxMouseY);

    if (o.maxY != null) ey = o.vmode ? Math.min(ey, o.maxMouseY) : Math.max(ey, o.minMouseY);



    nx = x + ((ex - o.lastMouseX) * (o.hmode ? 1 : -1));

    ny = y + ((ey - o.lastMouseY) * (o.vmode ? 1 : -1));



    if (o.xMapper)    nx = o.xMapper(y)

    else if (o.yMapper)  ny = o.yMapper(x)



    Drag.obj.root.style[o.hmode ? "left" : "right"] = nx + "px";

    Drag.obj.root.style[o.vmode ? "top" : "bottom"] = ny + "px";

    Drag.obj.lastMouseX  = ex;

    Drag.obj.lastMouseY  = ey;



    Drag.obj.root.onDrag(nx, ny);

    return false;

  },



  end : function()

  {

    document.onmousemove = null;

    document.onmouseup   = null;

    Drag.obj.root.onDragEnd(  parseInt(Drag.obj.root.style[Drag.obj.hmode ? "left" : "right"]), 

                  parseInt(Drag.obj.root.style[Drag.obj.vmode ? "top" : "bottom"]));

    Drag.obj = null;

  },



  fixE : function(e)

  {

    if (typeof e == 'undefined') e = window.event;

    if (typeof e.layerX == 'undefined') e.layerX = e.offsetX;

    if (typeof e.layerY == 'undefined') e.layerY = e.offsetY;

    return e;

  }

};