var sStep = 35; 
var sTimeout = 15;
var sLeft = 350;
var sRight = 350;
var wObj;

function winOpen()
{
	wObj.style.display = 'block';
	
	if (sLeft > 0)
	{
		sRight += sStep; 
		sLeft -= sStep; 		
		var rect = 'rect(auto, '+ sRight +'px, auto, '+ sLeft +'px)';		
		wObj.style.clip = rect;		
		setTimeout(winOpen, sTimeout); 
	}
}

function winClose()
{
	if (sLeft < sRight)
	{
		sRight -= sStep; 
		sLeft += sStep; 
		var rect = 'rect(auto, '+ sRight +'px, auto, '+ sLeft +'px)';
		wObj.style.clip = rect;
		setTimeout(winClose, sTimeout);
	}
	else wObj.style.display = 'none';
}