function pickupSubNavi(){

	document.getElementById('item-index').style.height = 'auto';
	document.getElementById('item-index').style.overflow = 'visible';
	document.getElementById('item-index').style.visibility = 'visible';
}
function vanishSubNavi(e){

	if(getMousePosition(e).y>document.getElementById('item-index').offsetTop+63 || getMousePosition(e).y<document.getElementById('item-index').offsetTop+33){
		document.getElementById('item-index').style.height = 'auto';
		document.getElementById('item-index').style.overflow = 'hidden';
		document.getElementById('item-index').style.visibility = 'hidden';
	}

}

function getMousePosition(event) {
	var obj = new Object();
	if (!event) var event=window.event;
	if (!event.pageX) event.pageX = event.clientX + document.body.scrollLeft;
	if (!event.pageY) event.pageY = event.clientY + document.body.scrollTop;
	obj.x = event.pageX;
	obj.y =  event.pageY;
	return obj;
}