function popup(myName, myId) {
	var winl = (screen.width - 400) / 2;
	var wint = (screen.height - 600) / 2;
	winprops = 'height='+600+',width='+400+',top='+wint+',left='+winl+',toolbar=no,location=no,menubar=no,status=no,scrollbars=auto,resizable=yes'
	win = window.open('http://www.vakantieboerderijen.nl/agenda.php?v_code='+myId, myName, winprops)
	if (parseInt(navigator.appVersion) >= 4) {
		win.window.focus();
	}
}