// bestellen & downloaden pagina
function toggleExpandable(id) {
	var prevId;
    var prevBody;
    var prevImg;

	var tbody = document.getElementById("tbExpandable" + id)
	var img = document.getElementById("imgExpandable" + id)
	
	if (prevBody && prevId != id) prevBody.style.display = "none";
	if (prevImg && prevId != id) prevImg.src = "gfx/+.gif";
	
	prevId = id;
	prevBody = tbody;
	prevImg = img;

	if (tbody) tbody.style.display = (tbody.style.display == "none") ? "block" : "none";
	if (img) img.src = (tbody.style.display == "none") ? "gfx/+.gif" : "gfx/-.gif";

	return false;
}

// contact form
function validateVoorwaarden(sender, args) {		
    var obj = document.getElementById('chkAkkoord');
   
	if (obj.checked==true) {
		args.IsValid = true;
		return;
	} else {
		args.IsValid = false;
		return;
	}
}

Array.prototype.inArray = function (value) {
	var i;
	for (i=0; i < this.length; i++) {
		if (this[i] === value) {
			return true;
		}
	}
	return false;
};

function isLeapYear(datea) {
	datea = parseInt(datea);

	if(datea%4 == 0) {
		if(datea%100 != 0) {
			return true;
		} else {
			if(datea%400 == 0)
				return true;
			else
				return false;
		}
	}
    return false;
}