function switchMenu(obj,obj2) {
	var el  = document.getElementById(obj);
	var el2 = document.getElementById(obj2);
	
	if (el.style.display != "block") {
		el.style.display = "block";
	} else {
		el.style.display = "none";
	}
	el2.style.backgroundImage=( (el.style.display=='none') ? 'url(common/images/icon_plus.gif)' : 'url(common/images/icon_minus.gif)');

}