var curr					= "";
var showHide				= function(el)
{
	var newid				= el.id+"_span";
	if(el.id.indexOf("top_") != -1)
	{
		if(curr == newid)
		{
			display(curr);
			curr			= "";
			return;
		}
		else if(curr != "")
		{
			display(curr);	
		}
		curr				= newid;
	}
	display(newid);
}

var display					= function(id)
{
	document.getElementById(id).style.display = (document.getElementById(id).style.display == "none") ?
		"block" :
		"none";
}