function OnMenu(menu) {
	
	var imgElt = 'imgMenu_'+menu;
	var imgOverElt = 'imgMenu_'+menu+'_over';
		
	document.getElementById(imgElt).style.display ="none";
	document.getElementById(imgOverElt).style.display ="block";
}

function OffMenu(menu) {

	var imgElt = 'imgMenu_'+menu;
	var imgOverElt = 'imgMenu_'+menu+'_over';
	
	document.getElementById(imgElt).style.display ="block";
	document.getElementById(imgOverElt).style.display ="none";
}