function resizediv(divname, diffheight) {
	winWidth=document.all?document.body.clientWidth:window.innerWidth;
	winHeight=document.all?document.body.clientHeight:window.innerHeight;
	
	var thisnav = document.getElementById(divname);
	if (thisnav.style.height+diffheight < winHeight) {
		thisnav.style.height = (winHeight-diffheight)+'px';
	}
}