var nAncho = 800;
var nAlto = 600;

function aumentar( oEnlace, bPantallaCompleta )
{
	if ( bPantallaCompleta )
		sParametros = 'fullscreen';
	else
		sParametros = 'width=' + nAncho + ',height=' + nAlto + ',left=' + ( ( screen.width / 2 ) - ( nAncho / 2 ) ) + ',top=' + ( ( screen.height / 2 ) - ( nAlto / 2 ) - 20 );
	open( oEnlace.href, oEnlace.target, sParametros );
}