// toggle_display method: toggle display of an object
function toggle_display(object){
	if(object.style.display == 'none'){
		object.style.display = 'block';
	} else {
		object.style.display = 'none';
	}
}

// toggle_display_group method: pre-define groups for toggling
function toggle_display_group(group){
	switch(group){
		case 'login':
			toggle_display(document.getElementById('userinput'));
			toggle_display(document.getElementById('userlogin'));
			toggle_display(document.getElementById('usercomments'));
			if(document.getElementById('userlogin').style.display == 'block'){
				document.getElementById('loginerror').innerHTML = '';
				document.getElementById('login').focus();
			}
			break;
		case 'mainlogin':
			toggle_display(document.getElementById('maininput'));
			toggle_display(document.getElementById('maininfo'));
			if(document.getElementById('maininput').style.display == 'block'){
				document.getElementById('mainloginerror').innerHTML = '';
				document.getElementById('mainlogin').focus();
			} 
			break;
	}
}