// Image preloader and switcher © www.ElasticBrand.com 2004 JCrosse
// prefix all button images "names" on the HTML page with "i".
// suffix all "up", normal button state image file names with "_n" and all rollover states with "_r"

var isLoaded = false;

function preloadImages()
{
	var args = (arguments.length > 0) ? true : false;
	var di = (document.images) ? true : false;
	if(args && di)
	{
		for(var x=0;x<arguments.length;x++)
		{
			eval(arguments[x]+'n = new Image();');
			eval(arguments[x]+'n.src = document.images[\'i'+arguments[x]+'\'].src;');
			eval(arguments[x]+'r = new Image();');
			eval(arguments[x]+'r.src = getRollover(document.images[\'i'+arguments[x]+'\'].src);');
			eval('document.images[\'i'+arguments[x]+'\'].onmouseover = function(){if(isLoaded){this.src = '+arguments[x]+'r.src}};');
			eval('document.images[\'i'+arguments[x]+'\'].onmouseout = function(){if(isLoaded){this.src = '+arguments[x]+'n.src}};');
		}
		isLoaded = true;
	}
}


function getRollover(imgsrc)
{
	if(imgsrc.indexOf('_n.')==-1)
	{
		alert('Error:\nThe images are not named correctly.\nPlease name them e.g. "someimage_n.gif"');
	}
	else
	{
		imgsrc = imgsrc.split('_n.');
		imgsrc = ''+imgsrc[0]+'_r.'+imgsrc[1];
		return imgsrc;
	}
}