leftpos=0;
heightpos=0;
if(screen)  {
	leftpos=screen.width-800
}

if(screen)  {
	heightpos=screen.height-600
}

function openwin()  {
	newWindow = window.open('ventanas/principal.htm','porr','toolbar=yes,location=no,status=no,scrollbars=no,resize=no,width=770,height=500,left='+leftpos+',top='+heightpos+'');
}

function closeWin()   {
	if (newWindow && !newWindow.closed)   {
		newWindow.close()
	}
}