var wallpapers = new Array();
var active_wallpaper = 0;

function next_wallpaper() {
	if (wallpapers.length == 0) {
		return false;
	}
	if (! set_wallpaper_by_number(active_wallpaper + 1)) {
		set_wallpaper_by_number(0);
	}
}

function set_wallpaper_by_number(n) {
	if (n >= wallpapers.length) {
		return false;
	}
	set_wallpaper(wallpapers[n]);
	active_wallpaper = n;
	return true;
}

function set_wallpaper(image) {
	if (image != "") {
		document.body.style.background = "#333333 url("+image+") repeat fixed";
		document.cookie = "Tapete="+image;
	} else {
		document.body.style.background = "#333333";
		document.cookie = "Tapete=";
	}
}

function fensterbreite() {
  if (window.innerWidth) {
    return window.innerWidth;
  } else if (document.body && document.body.clientWidth) {
    return document.body.clientWidth;
	} else if (document.documentElement && document.documentElement.clientWidth) {
		return document.documentElement.clientWidth;
  } else {
    return 0;
  }
}

function fensterhoehe() {
  if (window.innerHeight) {
    return window.innerHeight;
  } else if (document.body && document.body.clientHeight) {
    return document.body.clientHeight;
	} else if (document.documentElement && document.documentElement.clientHeight) {
		return document.documentElement.clientHeight;
  } else {
    return 0;
  }
}

function fenstergroesse() {
	return {x: fensterbreite(), y: fensterhoehe()};
}

function groesseAendern() {
	var margin = (fensterbreite() - 800) / 2;
	if (margin < 0) {
		margin = 0;
	}
	document.getElementById('body').style.marginLeft = margin + "px";
}

function start() {
	groesseAendern();
	window.onresize = groesseAendern;
	if (document.cookie) {
		var cookies = document.cookie.split(";");
		for (var i=0; i < cookies.length; i++) {
			var cookie = cookies[i].split("=");
			if (cookie[0] == "Tapete") {
				set_wallpaper(cookie[1]);
			}
		}
	}
}

function kontakt_pruefen() {
	var formular = document.kontakt_formular;

	document.getElementById("error_message").innerHTML = "";
	formular.nachricht.className = "textfield";
	formular.name.className = "textfield";
	formular.mail.className = "textfield";
	var ret = true;
	
	if (formular.nachricht.value == "") {
		formular.nachricht.className = "textfield error";
		document.getElementById("error_message").innerHTML = "Bitte überprüfen Sie die Angaben im markierten Feld.";
		ret = false;
	}
	if (formular.name.value == "") {
		formular.name.className = "textfield error";
		document.getElementById("error_message").innerHTML = "Bitte überprüfen Sie die Angaben im markierten Feld.";
		ret = false;
	}
	if (formular.mail.value == "") {
		formular.mail.className = "textfield error";
		document.getElementById("error_message").innerHTML = "Bitte überprüfen Sie die Angaben im markierten Feld.";
		ret = false;
	}
	return ret;
}

function set_info(text,text2,image) {
	var element = document.getElementById('info-text');
	if (element != null) {
		element.innerHTML = text;
	}
	element = document.getElementById('info-text2');
	if (element != null) {
		element.innerHTML = text2;
	}
	element = document.getElementById('preview');
	if ((element != null) && (image != '')) {
		element.src = image;
	}
}