function hideLevel( _levelId) {
	var thisLevel = document.getElementById( _levelId );
	thisLevel.style.display = "none";
	}
	
function showLevel( _levelId) {
	var thisLevel = document.getElementById( _levelId );
	if ( thisLevel.style.display == "none") {
		thisLevel.style.display = "block";
		}
	else {
		hideLevel( _levelId);
		}	
	}
//
//function showLevelOver( _levelId) {
//	var thisLevel = document.getElementById( _levelId );
//	if ( thisLevel.style.display == "none") {
//		thisLevel.style.display = "block";
//		}
//	}

//var plusImg = new Image();
//	plusImg.src = "imagenes/listaMenuDesplegable.jpg"
//var minusImg = new Image();
//	minusImg.src = "imagenes/listaMenuDesplegada.jpg"
//
//function hideLevel( _levelId, _imgId ) {
//	var thisLevel = document.getElementById( _levelId );
//	var thisImg = document.getElementById( _imgId );
//	thisLevel.style.display = "none";
//	thisImg.src = plusImg.src;
//	}
//	
//function showLevel( _levelId, _imgId ) {
//	
//	var thisLevel = document.getElementById( _levelId );
//	var thisImg = document.getElementById( _imgId );
//	if ( thisLevel.style.display == "none") {
//		thisLevel.style.display = "block";
//		thisImg.src = minusImg.src;
//		}
//	else {
//		hideLevel( _levelId, _imgId);
//		}
//		
//	}