var subMenu = null;
var lastMenu = null;

function fadeIn(obyek,step,delay, opacity) {
	opacity = opacity + step;

	if (opacity > 100) {
		opacity = 100;
	}

	document.getElementById(obyek).style.opacity = opacity / 100;

	if (opacity < 100) {
		subMenu = setTimeout('fadeIn("' + obyek + '",' + step + ',' + delay + ',' + opacity + ');',delay);
	} 
}

function fadeOut(obyek, step, delay, opacity) {
	if (opacity >= 100) {
		opacity = opacity - step;
		subMenu = setTimeout('fadeOut("' + obyek + '",' + step + ',' + delay + ',' + opacity + ');',200);
	} else {
		opacity = opacity - step;

		if (opacity <= 0) {
			opacity = 0;
		}

		var m = (obyek != '' ? document.getElementById(obyek) : null);
		if ( m ) {
		    m.style.opacity = opacity / 100;
		}

		if (opacity > 0) {
			subMenu = setTimeout('fadeOut("' + obyek + '",' + step + ',' + delay + ',' + opacity + ');',delay);
		} else if( m ) {
			m.style.display = 'none';
		}
	}
}


function changeMenuState (obyek) {
	if (lastMenu != null) {
		fadeOut(lastMenu,10,40, 100);
	}

	var m = (obyek != '' ? document.getElementById(obyek) : null);
	if (m && (m.style.opacity < 0.1)) {
		lastMenu = obyek;
		document.getElementById(obyek).style.display = 'block';
		fadeIn(obyek,10,40, 0);
	} else {
		fadeOut(obyek,10,40, 100);
		lastMenu = null;
	}
}