function doBack() {
	
	if (window.location.hash == '') {
		history.go(-1);
	} else {
		history.go(-2);
	}
	
	return false;
}

function makeAddress(input) {
	
	var output = "";
	var postfix = ["@", ".", ""];
	
	
	for (var i = 0; i < postfix.length; i++) {
		output += input[input.length - i - 1] + postfix[i];		
	}
	
	return output;
}

function navigateToAddress(input) {
	
	document.location.href = "mailto:" + makeAddress(input);	
}

function outputAddress(input) {
	
	document.write(makeAddress(input));	
}

function registerToNewsletter(lang) {
	
	var register_url = 'index.php?act=js/newsletter&lang=' + lang;
	var params = 'newsletter[name]=' + $( 'newsletter_name' ).value + '&newsletter[email]=' + $( 'newsletter_email' ).value;
	
	var ajaxRequest = new Ajax.Request(
		register_url, {
			method: 'post',
			parameters: params,
			onSuccess: function (req) {
				if(req.responseText && req.responseText != '') {
					$('newsletter').innerHTML = req.responseText;
				}
			}
		}
	);
}

function showRegistrationForm(identifier, lang) {
	
	$('registration_' + identifier).style.display = 'block';
	
	var registration_url = 'index.php?act=js/registration&lang=' + lang;
	var params = 'product_id=' + identifier;
	
	var ajaxRequest = new Ajax.Request(
		registration_url, {
			method: 'post',
			parameters: params,
			onSuccess: function (req) {
				if(req.responseText && req.responseText != '') {
					$('registration_' + identifier).innerHTML = req.responseText;
				}
			}
		}
	);
}

function hideRegistrationForm(identifier) {
	
	$('registration_' + identifier).style.display = 'none';
	$('registration_' + identifier).innerHTML = '';
}

function doRegistration(objForm, identifier) {
	
	var ajaxRequest = new Ajax.Request(
		root_url, {
			method: 'post',
			parameters: Form.serialize(objForm),
			onSuccess: function (req) {
				if(req.responseText && req.responseText != '') {
					$('registration_' + identifier).innerHTML = req.responseText;
				}
			}
		}
	);
	
	return false;
}

var currCourseId = 0;

function changeCourseDates(count) {
	
	var inputs = document.getElementsByTagName('input');
	
	for (var i = 0; i < inputs.length; i++) {
		
		if (inputs[i].checked == true) {
			
			inputs[i].checked = false;
		}
	}
	
	
	var courseId = $('course_select').options[$('course_select').selectedIndex].value;
	
	// hide old dates
	if (currCourseId != 0) {
		
		for (var i = 1; i <= (3 * count); i++) {
			
			if ($('course_date_' + currCourseId + '_' + i)) {
				
				$('course_date_' + currCourseId + '_' + i).style.display = 'none';
			}
		}
	}
	
	// show new dates
	for (var i = 1; i <= (3 * count); i++) {
		
		if ($('course_date_' + courseId + '_' + i)) {
			
			$('course_date_' + courseId + '_' + i).style.display = 'block';
		}
	}
	
	currCourseId = courseId;
}