var preload_imgs = new Array();

var popUpWin=0;
function popUpWindow(URLStr, left, top, width, height, scrollbars) {
  if(popUpWin)
  {
    if(!popUpWin.closed) popUpWin.close();
  }

	// center window
	w = screen.availWidth;
	h = screen.availHeight;

	var popW = width, popH = height;
	var leftPos = (w-popW)/2, topPos = (h-popH)/2;
	// end center window
  
	popUpWin = open(URLStr, 'popUpWin', 'toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars='+scrollbars+',resizable=yes,copyhistory=yes,width='+width+',height='+height+',left='+leftPos+', top='+topPos+',screenX='+leftPos+',screenY='+topPos+'');
}

function preloadImgs() {
	var args = preload_imgs;
	document.imageArray = new Array(args.length);
	for(var i=0; i<args.length; i++) {
		document.imageArray[i] = new Image;
		document.imageArray[i].src = args[i];
	}
}

function initHoverButtons() {
	var butElements = $('img.hvr');
	// run through all elements with 'hoverbutton' class:
	for (var i = 0; i < butElements.length; i++) {
		var elem = butElements[i];		
		preload_imgs.push(genHoverSrc(elem.src,2));
		elem.onmouseover = function() {
			this.src = genHoverSrc(this.src,2);
		}
		elem.onmouseout = function() {
			this.src = genHoverSrc(this.src,1);
		}
	}
}

function genHoverSrc(img_src, state) {
	var ext = img_src.substring(img_src.length-4,img_src.length);
	var pre_ext = img_src.substring(0,img_src.length-5);
	return(pre_ext + state.toString() + ext);
}