function sh(id)
{
	msg = document.getElementById("msg" + id);
	vis = msg.style.visibility;
	msg.style.visibility = (vis=="visible") ? "hidden" : "visible";
	msg.style.display = (vis=="visible") ? "none" : "";	
	plusminus = document.getElementById("tmsg" + id);
	plusminus.innerHTML = (vis=="visible") ? "+" : "-";		
}

function change(k, topic_id, message_n, direction)
{
	msg = document.getElementById("msg" + k);
	vis = msg.style.visibility;
	if (vis=="hidden") { getmessage(k, topic_id, message_n, direction); } else { hide(k); }	
}
function hide(k)
{
	msg = document.getElementById("msg" + k);
	vis = msg.style.visibility;
	msg.style.visibility = "hidden";
	msg.style.display = "none";	
	plusminus = document.getElementById("tmsg" + k);
	plusminus.innerHTML = "+";		
}
function show(k)
{
	msg = document.getElementById("msg" + k);
	vis = msg.style.visibility;
	msg.style.visibility = "visible";
	msg.style.display = "";	
	plusminus = document.getElementById("tmsg" + k);
	plusminus.innerHTML = "-";		
}

function LightOn()
{
	el = document.getElementById("top");
	el.style.color = "red";
}

function LightOff()
{
	el = document.getElementById("top");
	el.style.color = "black";
}

function LightChange()
{
	el = document.getElementById("top");
	el.style.color = (el.style.color == "red") ? "purple" : "red";
}

function str_replace(txt,cut_str,paste_str)
{
	var f=0;
	var ht='';
	ht = ht + txt;
	f=ht.indexOf(cut_str);
	while (f!=-1)
	{
		//цикл для вырезания всех имеющихся подстрок
		f=ht.indexOf(cut_str);
		if (f>=0) { ht = ht.substr(0,f) + paste_str + ht.substr(f+cut_str.length); };
	};
	return ht
}