function popUp(URL,width,height) {
	day = new Date();
	id = day.getTime();

	var winLeft = (screen.width - width) / 2;
	var winUp = (screen.height - height) / 2;

	eval("page" + id + " = window.open(URL, '" + id + "', 'toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=0,width='+width+',height='+height+',left='+winLeft+',top='+winUp);");
}


function contact_by_mail(user, domain, suffix, content) 
{
	if (!content)
	{
		document.write('<a href="' + 'mailto:' + user + '@' + domain + '.' + suffix + '">' + user + '@' + domain + '.' + suffix + '</a>');
	} else
	{
		document.write('<a href="' + 'mailto:' + user + '@' + domain + '.' + suffix + '">' + content + '</a>');
	}
	return true;
}

function change_arrangements(element)
{
	hide_arrangements()	
	document.getElementById('arstart').style.display = 'none'
	document.getElementById('arrangement_keuze').style.display = 'none'
	document.getElementById(element).style.display = 'block'
}

function hide_arrangements()
{
	document.getElementById('ar1').style.display = 'none'
	document.getElementById('ar2').style.display = 'none'
	document.getElementById('ar3').style.display = 'none'
	document.getElementById('ar4').style.display = 'none'
	document.getElementById('ar5').style.display = 'none'
	document.getElementById('ar6').style.display = 'none'
	document.getElementById('ar7').style.display = 'none'
	document.getElementById('ar8').style.display = 'none'
	document.getElementById('ar9').style.display = 'none'

}