function lightbox(withpadding,string,width,height){
	var amplada = $(window).width();
	var alcada = $(window).height();
	//var scrolled = $('body').scrollTop();
	var scrolled = $(window).scrollTop();
	$('body').prepend("<div class='lightbox'></div>");
	$('.lightbox').html("<div class='tancar'></div><div class='lightbox-content'>" + string + "</div>");
	if(height) $('.lightbox').css("height",height + "px");
	else{
		height = $('.lightbox').height();
		num = $(string).children('img').length;
		if(num%3 == 0) fact = num/3;
		else fact = (num + (3-(num%3))) / 3;
		height = height + (fact * 170);
	}
	$('.lightbox').css("width",width + "px");
	
	var posx = (amplada / 2) - (width / 2);
	var posy = (alcada / 2) - (height / 2);
	
	$('.lightbox').css("top",posy + scrolled + "px");
	$('.lightbox').css("left",posx + "px");
	if(withpadding==1){
		$('.lightbox-content').css("padding", "5% 10% 5% 10%");
		$('.lightbox-content').css("width", "80%");
	}
	
	$('.tancar').click(function(){
		$('.lightbox').html('');
		$('.lightbox').remove();
	});
	
}