function rollOn(obj) {
	var classNameOld = obj.className ;
	var classNameString = classNameOld.substring(classNameOld.charAt(0),classNameOld.indexOf('_')+1);
	var classNameState = classNameOld.split(classNameString)[1];
	var classNameNew = classNameString+'on';
	obj.className = classNameNew;
}
function rollOff(obj) {
	var classNameOld = obj.className ;
	var classNameString = classNameOld.substring(classNameOld.charAt(0),classNameOld.indexOf('_')+1);
	var classNameState = classNameOld.split(classNameString)[1];
	var classNameNew = classNameString+'off';
	obj.className = classNameNew;
}

function tdLink(nameHref) {
	document.location.href = document.getElementById(nameHref).href;
}

function ssMenu(divName) {
	document.getElementById(divName).style.display='block';
}

function closeDiv() {
	var divArray = new Array;
	divArray = ['divMedecine','divBiologie','divSante','divAgronomie'];
	for (i=0 ; i<divArray.length ; i++) {
		document.getElementById(divArray[i]).style.display='none';
	}
}