function swapimg(imgname,chg){
	document.images[imgname].src = chg;
}

data = new Array("images/1_1.gif","images/2_1.gif","images/3_1.gif","images/4_1.gif","images/5_1.gif");
preload= new Array();
for (i=0; i<data.length; i++)
{
	preload[i] = new Image();
	preload[i].src = data[i];
}