function autosize(){
	var el = document.getElementsByTagName('body')[0];
	var cur = el.offsetHeight - 55;
	var total_height = $('content').offsetHeight+$('logo').offsetHeight+$('piano').offsetHeight;
//	alert(cur +' ' + total_height);
	if( total_height < cur){
		$('content').style.height = cur -$('piano').offsetHeight - $('logo').offsetHeight +'px';
	}
	$('menu').style.height = $('content').offsetHeight - 40 + 'px';
} // function autosize

// zet de onresize in de body tag (werkt alleen goed in FF)
//test = document.getElementsByTagName('body')[0];
//test.setAttribute('onresize','autosize();');} // function autosize