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