// AJAX
var http_request = false;

function createRequest(url, contentLayer, loadingLayer) {

	document.getElementById(loadingLayer).style.visibility = 'visible';
	document.getElementById(loadingLayer).style.display = 'block';

	http_request = false;

	if (window.XMLHttpRequest) { // Mozilla, Safari,...
		http_request = new XMLHttpRequest();
		if (http_request.overrideMimeType) {
			http_request.overrideMimeType('text/xml');
		}
	} else if (window.ActiveXObject) { // IE
		try {
			http_request = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try {
				http_request = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (e) {}
		}
	}

	if (!http_request) {
		alert('Cannot create an XMLHTTP instance');
		document.getElementById(loadingLayer).style.visibility = 'hidden';
		document.getElementById(loadingLayer).style.display = 'none';
		return false;
	}

	http_request.onreadystatechange = function () { writeContent(contentLayer, loadingLayer); };
	http_request.open('GET', url, true);
	http_request.send(null);

	return true;
}

function writeContent (contentLayer, loadingLayer) {
	if (http_request.readyState == 4) {
	    if (http_request.status == 200) {
	    	var contentDIV = document.getElementById(contentLayer);
			contentDIV.innerHTML = http_request.responseText;
	    } else {
	        alert('There was a problem with the request.');
	    }
	    document.getElementById(loadingLayer).style.visibility = 'hidden';
	    document.getElementById(loadingLayer).style.display = 'none';
	}
}

// Rating

function rating_on (num) {
	for (var i = 1; i<=num; i++) {
		document.getElementById('rating_'+i).src = '/images/rating_1.png';
	}
}

function rating_off (num) {
	for (var i = 1; i<=num; i++) {
		document.getElementById('rating_'+i).src = '/images/rating_0.png';
	}
}

function do_popup (url, name, option) {
	window.open(url, name, option);

	return false;
}

function do_history_back () {
	history.go(-1);
	return false;
}

// Alles schwarz weiß machen
function blacknwhite () {
	var html_tags = new Array('body', 'h1', 'h2', 'h3', 'h4', 'span', 'p', 'div', 'ul', 'li', 'a');

	for (var tag_name in html_tags) {
		var loop = true;
		var counter = 0;
		while (loop) {
			if (document.getElementsByTagName(html_tags[tag_name])[counter]) {
				document.getElementsByTagName(html_tags[tag_name])[counter].style.color = '#000';
				document.getElementsByTagName(html_tags[tag_name])[counter].style.border = '#000';
				document.getElementsByTagName(html_tags[tag_name])[counter].style.background = '#fff';
				counter++;
			} else {
				loop = false;
				counter = 0;
			}
		}
	}
}

/* Fuer das Content Modul */

function change_tab(active_tab) {
	var i = 1;
	while (document.getElementById('tab_'+i)) {
		if ('tab_'+i == active_tab) {
			document.getElementById('tab_'+i).className = "active_tab";
			document.getElementById('tab_list_'+i).style.visibility = "visible";
			document.getElementById('tab_list_'+i).style.display = "block";
		} else {
			document.getElementById('tab_'+i).className = "tab";
			document.getElementById('tab_list_'+i).style.visibility = "hidden";
			document.getElementById('tab_list_'+i).style.display = "none";
		}
		i++;
	}
}