// Drag'n'drop funcionality

N = (document.all) ? 0 : 1;
var ob;	// the object's style (IE)
var obObj; // the real object (IE)

var linked_obs; // list of linked objects

function MD(e) 
{
	if (N) {
		ob = document.layers[e.target.name];
		X=e.x;
		Y=e.y;
		return false;
	}
	else
	{
		obObj = event.srcElement.parentElement;
		ob = obObj.style;
		X=event.offsetX;
		Y=event.offsetY;
		if(obObj.tagName.toLowerCase() != "div") obObj = null; // only take divs.
		else
		{	
			oxp = getPosFromId(obObj.id,"x");
			oyp = getPosFromId(obObj.id,"y");
			chunknr = pieces_inchunk[oyp][oxp];
			if (chunknr != null)
			{
				linked_obs = new Array();
//				window.status = "IS PART OF "+chunknr;
				for(i=0;i<chunks[chunknr].length;++i)
				{
					window.status="object "+obObj.id+" is linked to "+chunks[chunknr][i];
					linked_obs[i] = new Array();
					linked_obs[i]["id"] = chunks[chunknr][i];

					linked_obs[i]["xdiff"] = eval("document.all."+obObj.id+".style.pixelLeft") - eval("document.all."+chunks[chunknr][i]+".style.pixelLeft");
					linked_obs[i]["ydiff"] = eval("document.all."+obObj.id+".style.pixelTop") - eval("document.all."+chunks[chunknr][i]+".style.pixelTop");
//					alert("x:"+linked_obs[i]["xdiff"]+",y:"+linked_obs[i]["ydiff"])
				}
			}
		}
//		alert ("j"+obObj);
	}
}

function MM(e) 
{
	if (ob) 
	{
		if (N) 
		{
			ob.moveTo((e.pageX-X), (e.pageY-Y));
		}
		else 
		{
			ob.pixelLeft = event.clientX-X + document.body.scrollLeft;
			ob.pixelTop = event.clientY-Y + document.body.scrollTop;
			// do rest of group
			if (!(linked_obs == null))
			{
				for(i=0;i<linked_obs.length;++i)
				{
					tmpobj = eval("document.all."+linked_obs[i]["id"]+".style");
					tmpobj.pixelLeft = ob.pixelLeft - linked_obs[i]["xdiff"];
					tmpobj.pixelTop = ob.pixelTop - linked_obs[i]["ydiff"];
				}
			}
			return false;
	      }
 	}
}

function MU() 
{
	if(obObj != null)
	{
		if(!N)
		{
			linkToPartner(obObj.id); // try to find docked partners
			obObj = null;
			linked_obs = null;
		}
	}
	ob = null;
}

if (N) 
{
	document.captureEvents(Event.MOUSEDOWN | Event.MOUSEMOVE | Event.MOUSEUP);
}

document.onmousedown = MD;
document.onmousemove = MM;
document.onmouseup = MU;