var opened = 0;
function showHide(obj) {
	if(obj.offsetHeight == 0) {
		obj.style.display='block';
	} else {
		obj.style.display='none';
	}
}
function showImage(num) {
	if (opened != 0) hideImage(opened);
	document.getElementById("popup_image_" + num).style.display = "block";
	opened = num;
}	
function hideImage(num) {
	document.getElementById("popup_image_" + num).style.display = "none";
	opened = 0;
}