function activatemenu(menu) {
	closeAllMenus();
	document.getElementById(menu).style.display = 'block';
	}
function closeAllMenus() {	
	var x;
	var sections = getElementsByClassName('submenu');
	for (x in sections)
		{sections[x].style.display = 'none';}
	}
function getElementsByClassName(clsName) 
{ 
	var arr = new Array(); 
	var elems = document.getElementsByTagName("*");
	for ( var cls, i = 0; ( elem = elems[i] ); i++ )
	{
		if ( elem.className == clsName )
		{
			arr[arr.length] = elem;
		}
	}
	return arr;
}