function toggle(el) {
	var el = $(el);
	el.style.display = (el.style.display == 'none' ? el.style.display = '' : el.style.display = 'none');
}

function blanket_size(blanket) {
	if (typeof window.innerHeight != 'undefined') {
		viewportHeight = window.innerHeight;
	} else {
		viewportHeight = document.documentElement.clientHeight;
	}
    
	if ((viewportHeight > document.body.parentNode.scrollHeight) && (viewportHeight > document.body.parentNode.clientHeight)) {
		blanket_height = viewportHeight;
	} else {
		if (document.body.parentNode.clientHeight > document.body.parentNode.scrollHeight) {
			blanket_height = document.body.parentNode.clientHeight;
		} else {
			blanket_height = document.body.parentNode.scrollHeight;
		}
	}
	var blanket = $(blanket);
	blanket.style.height = blanket_height + 'px';
}

function window_pos(popup) {
	if (typeof window.innerWidth != 'undefined') {
		viewportwidth = window.innerWidth;
        viewportheight = window.innerHeight;
	} else {
		viewportwidth = document.documentElement.clientWidth;
        viewportheight = document.documentElement.clientHeight;
	}
    
	var popup = $(popup);
    popup.style.display = '';
    popup.style.left = ((viewportwidth - popup.offsetWidth) / 2) + 'px';
    popup.style.top = ((viewportheight - popup.offsetHeight) / 2) + 'px';
    popup.style.display = 'none';
}

function open_popup(blanket, popup) {
	blanket_size(blanket);
	window_pos(popup);
	toggle(blanket);
	toggle(popup);		
}

function close_popup(blanket, popup) {
    toggle(blanket);
    toggle(popup);
}