function initMenu() {
    var name = getRelative(document.URL);
    if (name == '') name = 'index.html';
    var links = document.getElementById('Menu').getElementsByTagName("a");
    for (var j = 0; j < links.length; j++) {
        if (getRelative(links[j].href) == name) {
            links[j].className = 'selected';
        }
    }
}
function getRelative(url) {
    return url.substring(url.lastIndexOf('/')+1);
}

function checkMandatory(form) {
	var message = '';
	var broken = undefined;
	var textfields = ['firstname','lastname','affiliation','country','email'];
	var optionfields = ['profile','hotel'];

	for (var i = 0; i < textfields.length; i++) {
		var field = form.elements[textfields[i]];
		if (WithoutContent(field.value)) {
			if (broken == undefined) {
				broken = field;
			}
			message += '  * ' + textfields[i] + '\n';
		}
	}
	for (var i = 0; i < optionfields.length; i++) {
		var field = form.elements[optionfields[i]];
		if (NoneWithCheck(field)) {
			if (broken == undefined) {
				broken = field[0];
			}
			message += '  * ' + optionfields[i] + '\n';
		}
	}
	
	
	if (broken != undefined) {
		broken.focus();
		alert('The following fields are required: \n' + message);
		return false;
	} else {
		return true;
	}
}




function WithoutContent(ss) {
	if(ss.length > 0) { return false; }
	return true;
}

function NoneWithContent(ss) {
	for(var i = 0; i < ss.length; i++) {
		if(ss[i].value.length > 0) { return false; }
	}
	return true;
}

function NoneWithCheck(ss) {
	for(var i = 0; i < ss.length; i++) {
		if(ss[i].checked) { return false; }
	}
	return true;
}

function WithoutCheck(ss) {
	if(ss.checked) { return false; }
	return true;
}

function WithoutSelectionValue(ss) {
	for(var i = 0; i < ss.length; i++) {
		if(ss[i].selected) {
			if(ss[i].value.length) { return false; }
		}
	}
	return true;
}