var listeners = [];

function loadListeners(){
	for(var i = 0; i < listeners.length; i++)
		listeners[i]();
}

var dom = (document.getElementById)? true : false;
var nn4 = (document.layers)? true : false;
var ie = (document.all)? true : false;
var opera = (navigator.userAgent.indexOf('Opera') >= 0)? true : false;

function showElem()
{
	var a = showElem.arguments;
	
	if (a != null)
	{	
		for (i = 0; i < a.length; i ++)
		{
			if (dom)
			{
				document.getElementById(a[i]).style.visibility = 'visible';
	        }
			else if (ie)
			{
				document.all[a[i]].style.visibility = 'visible';
			}
			else if (nn4)
			{
				eval("document." + a[i] + ".visibility = 'visible'");
			}
			else
			{
				alert('Your brouser doesn'+"'"+'t allow to change visibility');
			}
		}
	}
}

function hideElem()
{
	var a = hideElem.arguments;

	if (a != null)
	{		
		for (i = 0; i < a.length; i ++)
		{
			if (dom)
			{
				document.getElementById(a[i]).style.visibility = 'hidden';
			}
			else if (ie)
			{
				document.all[a[i]].style.visibility = 'hidden';
			}
			else if (nn4) 
			{ 
				eval("document." + a[i] + ".visibility = 'hide'");
			}
			else
			{
				alert('Your brouser doesn'+"'"+'t allow to change visibility');
			}
		}
	}
}