function Coord(x, y)
{
	this.x = (!x)?0:x;
	this.y = (!y)?0:y;
  
	this.toString	= objToString;
	this.equals		= equalsCoord;
}

function Canvas(x, y, width, height)
{
	this.width	= (!width)?0:width;
	this.height = (!height)?0:height;
  
	this.Coord	= Coord;
	this.Coord(x, y);
  
	this.equalsCoord	= this.equals;
	this.equals			= equalsCanvas;
}

function objToString()
{
	var ret = "{";
	for(p in this )
	{
		if (typeof this[p] == "function" || typeof this[p] == "object") continue;
		if(ret.length > 1)
			ret += ",";
		ret += p + ":" + this[p];
	}
	return ret + "}";
}

function equalsCoord(/*Coord*/ c)
{
	return (this.x == c.x && this.y == c.y);
}
function equalsCanvas(/*Canvas*/ c)
{
	return ( this.equalsCoord == c.equalsCoord && this.width == c.width && this.height == c.height);
}

function getLayerRef(id, document)
{
	if(!document)
		document = window.document;
	if(document.layers) 
	{
		for(var l = 0; l < document.layers.length; l++)
			if (document.layers[l].id == id)
				return document.layers[l];
		for(var l = 0; l < document.layers.length; l++) 
		{
			var result = getLayerRef(id, document.layers[l].document);
			if(result)
				return result;
		}
		return null;
	}
	else if(document.all)
	{
		return document.all[id];
	}
	else if(document.getElementById)
	{
		return document.getElementById(id);
	}
	else
	{
		return null;
	}
}

function setPosition(objLayer, coords)
{
    if(document.layers) 
    {
		objLayer.top				= coords.y;
		objLayer.left				= coords.x;
    } 
    else if(window.opera) 
    {
		objLayer.style.top			= coords.y;
		objLayer.style.left			= coords.x;
    } 
    else if(document.all) 
    {
		objLayer.style.top			= coords.y;
		objLayer.style.pixelLeft	= coords.x;
    } 
    else if(document.getElementById) 
    {
		objLayer.style.top			= coords.y + 'px'; 
		objLayer.style.left			= coords.x + 'px';
    }
}

function setPositionById(id, coords)
{
	var objLayer = getLayerRef(id);
	if(typeof objLayer == undefined) return;
  
	if(document.layers)
	{
		objLayer.top				= coords.y;
		objLayer.left				= coords.x;
	} 
	else if(window.opera)
	{
		objLayer.style.top			= coords.y;
		objLayer.style.left			= coords.x;
	} 
	else if(document.all) 
	{
		objLayer.style.top			= coords.y;
		objLayer.style.pixelLeft	= coords.x;
	} 
	else if(document.getElementById) 
	{
		objLayer.style.top			= coords.y + 'px'; 
		objLayer.style.left			= coords.x + 'px';
	}
}


function setVisibility(objLayer, visible) 
{
	if(document.layers)
	{
		objLayer.visibility			= (visible == true) ? 'show' : 'hide';
	} 
	else 
	{
		objLayer.style.visibility	= (visible == true) ? 'visible' : 'hidden';
	}
}

function setVisibility4DivByPrefix(prefix, visible, d)
{
	if(!d)
		d = window.document;

	if(document.layers)
	{
		for (var l = 0; l < d.layers.length; l++)
		{
			if(d.layers[l].id.substr(0, prefix.length ) == prefix)
				setVisibility(d.layers[l], visible);
			setVisibility4DivByPrefix(prefix,visible,d.layers[l].document);
		}
	} 
	else if(document.all)
	{
		var layers = document.all.tags("div"); 
		for(i=0; i < layers.length; i++) 
		{ 
			if(layers[i].id.substr(0, prefix.length ) == prefix )
				setVisibility(document.all.tags("div")[i], visible);
		}
	} 
	else if(document.getElementsByTagName)
	{
		var layers = document.getElementsByTagName("div");
		for(i=0; i < layers.length; i++)
		{
			if(layers[i].id.substr(0, prefix.length ) == prefix)
				setVisibility(layers[i], visible);
		}
	}
}

function getMouseXY(evt) 
{
	e = evt || window.event;
	if(!e) return null;
  
	if(document.layers) 
	{
		return new Coord(e.pageX, e.pageY);
	}
	else if(window.opera)
	{
		return new Coord(e.clientX, e.clientY);
	}
	else if(document.all ) 
	{
		return new Coord(e.x + document.body.scrollLeft, e.y + document.body.scrollTop);
	}
	else if(document.getElementById)
	{
		return new Coord(e.pageX , e.pageY );
	}
}

function /*out: Coord*/ getLayerCoords( /*in: HTML-Object*/ objLayer )
{
	var coords = new Coord();
  
	if(document.layers) 
	{
		coords.y = objLayer.top;
		coords.x = objLayer.left;
	} 
	else if( window.opera ) 
	{
		coords.y = objLayer.style.top;
		coords.x = objLayer.style.left;
	} 
	else if(document.all) 
	{
		o = objLayer;
		while(o.offsetParent)
		{
			coords.y += parseInt(o.offsetTop);
			coords.x += parseInt(o.offsetLeft);
			o = o.offsetParent;
		}
	} 
	else if(document.getElementById) 
	{
		coords.y = parseInt( document.defaultView.getComputedStyle(objLayer, '').getPropertyValue('top') ); 
		coords.x = parseInt( document.defaultView.getComputedStyle(objLayer, '').getPropertyValue("left") );
	}
  return coords;
}

function /*out: Coord*/ getLayerCoordsById( /*in: String*/ id )
{
	var objLayer = getLayerRef(id);
	var coords = new Coord();
  
	if(document.layers) 
	{
		coords.y = objLayer.top;
		coords.x = objLayer.left;
	} 
	else if(window.opera) 
	{
		coords.y = objLayer.style.top;
		coords.x = objLayer.style.left;
	} 
	else if(document.all) 
	{
		o = objLayer;
		while(o.offsetParent) 
		{
			coords.y += parseInt(o.offsetTop);
			coords.x += parseInt(o.offsetLeft);
			o = o.offsetParent;
		}
	} 
	else if(document.getElementById) 
	{
		coords.y = parseInt( document.defaultView.getComputedStyle(objLayer, '').getPropertyValue('top') ); 
		coords.x = parseInt( document.defaultView.getComputedStyle(objLayer, '').getPropertyValue("left") );
	}
	return coords;
}