function validate(form,lang) {
	var quantity = form.quantity;
	if (!quantity.value.length || !(parseInt(quantity.value)>0)){
		if (lang=="is") alert("Vantar aš setja inn magn.");
		else alert("Enter a valid quantity.");
		quantity.focus();
		return false;
	}
	quantity.value = parseInt(quantity.value);
	if (lang=="is") return confirm ('Viltu setja vöruna ķ körfuna?');
	else return confirm ('Do you want to add this product to shopcart?');
}
function popup(url, title, W, H, features){
	var X = Math.ceil((window.screen.availWidth - W) / 2);
	var Y = Math.ceil((window.screen.availHeight - H) / 2);
	features = "width=" + W + ", height=" + H + ", left=" + X + ", top=" + Y + ", " + features;
	window.open(url, title, features);
}