function toggle(id){
	var mydiv = document.getElementById(id);
	mydiv.style.display = (mydiv.style.display=='block'?'none':'block');
}
function display() {
	var hidden = getElementsByClassName('hidden');
	var visible = getElementsByClassName('visible');
	 
	for(i=0;i<hidden.length;i++) {  
		hidden[i].style.display = "none";  
	} 	
	for(i=0;i<visible.length;i++) {  
		visible[i].style.display = "block";  
	} 
}