function maskDiv(divs, mask){ //array, pos_in_array
	for(var i = 0; i < divs.length; i++){
		document.getElementById(divs[i]).style.display = "none";
	}
	document.getElementById(divs[mask]).style.display = "block";
}

var last_obj = null;
function toggleClass(obj){
	//alert(obj.className);
	if(last_obj != null)
	 last_obj.className = "";
	if(obj.className.indexOf("active") == 0)
		obj.className = "";
	else obj.className = "active";
	last_obj = obj;
}