function preLoad() {
	if(document.images)  {
		var argLen = arguments.length;
		for(var i = 0; i < argLen; i++) {
			var arg = arguments[i];
			self[arg] = new Image();
			self[arg].src = arg;
		}
	}
}

function PortfolioChooseImage( url, num){
	window.document.getElementById('main-portfolio-image').src = url;
	window.document.getElementById('main-portfolio-image').title = num;
}
function setElementOpacity(sElemId, nOpacity)
{
  var opacityProp = getOpacityProperty();
  var elem = document.getElementById(sElemId);
  

  if (!elem || !opacityProp) return; 
  
  if (opacityProp=="filter")  
  {
    nOpacity *= 100;
	

    var oAlpha = elem.filters['DXImageTransform.Microsoft.alpha'] || elem.filters.alpha;
    if (oAlpha) oAlpha.opacity = nOpacity;
    else elem.style.filter += "progid:DXImageTransform.Microsoft.Alpha(opacity="+nOpacity+")"; 
  }
  else 
    elem.style[opacityProp] = nOpacity;
}

function getOpacityProperty()
{
	//alert(navigator.appVersion.match(/MSIE ([\d.]+);/));
  if (typeof document.body.style.opacity == 'string') // CSS3 compliant (Moz 1.7+, Safari 1.2+, Opera 9, IE7)
    return 'opacity';
  else if (typeof document.body.style.MozOpacity == 'string') // Mozilla 1.6 and --, Firefox 0.8 
    return 'MozOpacity';
  else if (typeof document.body.style.KhtmlOpacity == 'string') // Konqueror 3.1, Safari 1.1
    return 'KhtmlOpacity';
  else if (document.body.filters && navigator.appVersion.match(/MSIE ([\d.]+);/)[1]>=5.5) // Internet Exploder 5.5+
    return 'filter';

  return false; //else
}