function openWindow(url, height, width, name){
   var left = Math.floor( (screen.width - width) / 2);
   var top = Math.floor( (screen.height - height) / 2);   
   var winParms = "top=" + top + ",left=" + left + ",height=" + height + ",width=" + width;
   winParms += ",status=no,toolbar=no,menubar=no,location=no,scrollbars=no";   
   var win = window.open(url, name, winParms);
   if (parseInt(navigator.appVersion) >= 4) { win.window.focus(); }
}
function swapImage(id, src) {
	document.getElementById(id).style.backgroundImage = "url('" + src + "')";
}