/* Preload img */

	nav = (document.layers)? true:false
	iex = (document.all)? true:false
		 function preload(imgObj,imgSrc){
	eval(imgObj+' = new Image()');
	eval(imgObj+'.src = "'+imgSrc+'"');
	
}

preload('img1','img/6_dsf.gif');
preload('img1on','img/6_dsf_on.giff');
preload('img2','img/6_dhs.gif');
preload('img2on','img/6_dhs_on.gif');
preload('img3','img/6_ds.gif');
preload('img3on','img/6_ds_on.gif');
preload('img4','img/6_dcl.gif');
preload('img4on','img/6_dcl_on.gif');
preload('img5','img/6_dtc.gif');
preload('img5on','img/6_dtc_on.gif');


/* tabella che si espande*/
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);
		}
	}