function correct_overlay () {
	var i   = 1;
	var obj = document.getElementById('img_'+i);
	while (obj != null){
		project_overlay(obj, i);
		i++;
		obj = document.getElementById('img_'+i);
	}
}

function project_overlay(obj, id) {
	// bepaal table positie
	var tableLeft = 0;
	var tableTop  = 0;
	var table = document.getElementById('content_table');
	if (table.offsetParent) {
		do {
			tableLeft += table.offsetLeft;
			tableTop += table.offsetTop;
		} while (table = table.offsetParent);
	}
	
	// bepaal afbeelding posistie
	var curleft = 0;
	var curtop  = 0;
	if (obj.offsetParent) {
		do {
			curleft += obj.offsetLeft;
			curtop += obj.offsetTop;
		} while (obj = obj.offsetParent);
	}
	
	var div = document.getElementById('overlay_'+id);
	var extra = 0;
	if (!need_scrolling('left')){
		extra = 18;
	}
	div.style.left = (curleft-tableLeft+extra)+'px';
	//div.style.top  = ((curtop-tableTop+extra)+60)+'px';
	div.style.top  = ((curtop-tableTop+extra)+0)+'px';
}

function project_overlay_over(id){
	document.getElementById('overlay_'+id).className = 'overlay_over';
}

function project_overlay_out(id){
	document.getElementById('overlay_'+id).className='overlay_out';
}	

function set_active_image(id){
	var i = 1;
	var img = document.getElementById('thumb_'+i);
	while (img != null){
		img.className='img_opacity';
		i++;
		img = document.getElementById('thumb_'+i);
	}
	document.getElementById('thumb_'+id).className='img';
}

function showSubNav(id, hoofd_id){
	document.getElementById('subnav').innerHTML = "<table cellpadding='0' cellspacing='0'><tr><td width='18'>&nbsp;</td><td class='submenu'><a href=?id="+id+"&hoofd_id="+hoofd_id+"&page=gerealiseerd'>REEDS GEREALISEERD</a>&nbsp;&nbsp;&nbsp;</td><td class='submenu'><a href=?id="+id+"&hoofd_id="+hoofd_id+"&page=ontwikkeling'>IN ONTWIKKELING</a>&nbsp;&nbsp;&nbsp;</td><td class='submenu'><a href=?id="+id+"&hoofd_id="+hoofd_id+"&page=renovatie'>RENOVATIE&nbsp;</a>&nbsp;&nbsp;</td>";
}
function hideSubNav(){
	document.getElementById('subnav').innerHTML = "";
}

function heroUsage(id) {
  pagina = escape(document.location.href);
  ref = escape(document.referrer);
  if((ref == "") || (ref == "undefined")){ ref = "favorieten"; }
  screensize = screen.width + "x" + screen.height;
  screencolor = (navigator.appName.indexOf("Microsoft") > -1) ? screen.colorDepth : screen.pixelDepth;
  document.frames['hero_usage'].location="usage/statistieken_save.php?pagina="+pagina+"&referrer="+ref+"&screensize="+screensize+"&screencolor="+screencolor+"&pages_id="+id+"";
}

var timer;
var direction;
var oldPosition = 0;

function scrollFrame(direction) {
                if(direction == 'left'){
                               timer = setInterval("doScroll('left');",20);
                }
                else if(direction == 'right'){
                               timer = setInterval("doScroll('right');",20);
                }
                else if(direction == 'up'){
                               timer = setInterval("doScroll('up');",20);
                }
                else if(direction == 'down'){
                               timer = setInterval("doScroll('down');",20);
                }
}

function stopScroll(){
				clearInterval(timer);
}

function doScroll(direction){
                if(direction == 'left'){ 
                               document.getElementById('contentDiv').scrollLeft -= 4;
                }
                else if(direction == 'right'){
                               document.getElementById('contentDiv').scrollLeft += 4;
                }
                else if(direction == 'down'){
                               document.getElementById('contentDiv').scrollTop += 4;
                }
                else if(direction == 'up'){
                               document.getElementById('contentDiv').scrollTop -= 4;
                }
}

function scrollFrame2(direction) {
                if(direction == 'left'){
                               timer = setInterval("doScroll2('left');",20);
                }
                else if(direction == 'right'){
                               timer = setInterval("doScroll2('right');",20);
                }
                else if(direction == 'up'){
                               timer = setInterval("doScroll2('up');",20);
                }
                else if(direction == 'down'){
                               timer = setInterval("doScroll2('down');",20);
                }
}

function doScroll2(direction){
                if(direction == 'left'){ 
                               document.getElementById('contentDiv2').scrollLeft -= 4;
                }
                else if(direction == 'right'){
                               document.getElementById('contentDiv2').scrollLeft += 4;
                }
                else if(direction == 'down'){
                               document.getElementById('contentDiv2').scrollTop += 4;
                }
                else if(direction == 'up'){
                               document.getElementById('contentDiv2').scrollTop -= 4;
                }
}