function hidediv(id) {
	//safe function to hide an element with a specified id
	if (document.getElementById) { // DOM3 = IE5, NS6
		document.getElementById(id).style.display = 'none';
	}
	else {
		if (document.layers) { // Netscape 4
			document.id.display = 'none';
		}
		else { // IE 4
			document.all.id.style.display = 'none';
		}
	}
}

function showdiv(id) {
	//safe function to show an element with a specified id
		  
	if (document.getElementById) { // DOM3 = IE5, NS6
		document.getElementById(id).style.display = 'block';
	}
	else {
		if (document.layers) { // Netscape 4
			document.id.display = 'block';
		}
		else { // IE 4
			document.all.id.style.display = 'block';
		}
	}
}

var current = 'f1';

function changefbox(new_id)
{
   if(current != new_id)
   {		
   	hidediv(current + '_btn_active');
   	showdiv(current + '_btn');
   	
    hidediv(current + '_info');
    showdiv(new_id + '_info');
    
    current = new_id;
    
    hidediv(current + '_btn');
   	showdiv(current + '_btn_active');
   }
   
   return false;
}