function windowHeight(){
	var alto= 0;
	if( typeof( window.innerWidth ) == 'number' ) {
		alto= window.innerHeight;
	} else if( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) {
		alto= document.documentElement.clientHeight;
	} else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) {
		alto= document.body.clientHeight;
	}
	return alto;
}