function selected(toSelect,divId,className){
	var items=document.getElementById(divId).childNodes;
	for (i=0;i<items.length;i++)
		{
		if (items[i].nodeType==1){	
			if(items[i].id==toSelect )
				{
				items[i].className=items[i].className + ' ' + className ;
				}
			else{
				items[i].className=items[i].className.replace(' ' + className,'')
				}
			}
		}
}

function setFontSize(fs) {
	var newFs = 0;
	switch(fs) {
		case 'normal':
			newFs = '1em';
			selected('normal','box_FontSize','selected');
		break;
        case 'medium': 
            newFs = '1.1em';
			selected('medium','box_FontSize','selected');
		break;
		case 'big':
			newFs = '1.2em';
			selected('big','box_FontSize','selected');
		break;
	}
	document.body.style.fontSize = newFs;
}