function imgpreload()
{
	var i = 0;
	// create object
	imageObj = new Image();
	// set image list
	images = new Array();
	images[0]="../images/aboutover.gif";
	images[1]="../images/contactover.gif";
	images[2]="../images/systemsover.gif";
	images[3]="../images/homeover.gif";
	images[3]="../images/buildover.gif";
	// start preloading
	for(i=0; i<imageObj.length; i++)
	{
		imageObj.src=images[i];
	}
}
function swapover(id)
{
	swapId(id, true);
}
function swapout(id)
{
	swapId(id, false);
}
function swapId(id, s)
{
	var img = document.getElementById(id);
	var imgsrc = "images/" + id;
	if(s)
		imgsrc += "over";
	imgsrc += ".gif";
	img.src = imgsrc;
}
// JavaScript Document