// navigation

function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		stage_nav1_over = newImage("../images/stage-nav1_over.jpg");
		stage_nav2_over = newImage("../images/stage-nav2_over.jpg");
		stage_nav3_over = newImage("../images/stage-nav3_over.jpg");
		stage_nav4_over = newImage("../images/stage-nav4_over.jpg");
		nav1_over = newImage("../images/nav1-over.gif");
		nav2_over = newImage("../images/nav2-over.gif");
		nav3_over = newImage("../images/nav3-over.gif");
		nav4_over = newImage("../images/nav4-over.gif");
		preloadFlag = true;
	}
}

// dropdown
function navChange(formName, popupName, target) {
	var popup = document[formName].elements[popupName];
	if (popup.options[popup.selectedIndex].value != "") {
        window.open(popup.options[popup.selectedIndex].value, target);
        popup.selectedIndex=0;
    }
}

// check form Kontaktformular
function chkFormular () {
	var message = document.getElementById("empty_field");
	message.style.display = "none";
	if (document.Kontaktformular.Vorname.value == "") {
	  document.Kontaktformular.Vorname.focus();
	  message.style.display = "block";
	  return false;
	}
	if (document.Kontaktformular.Name.value == "") {
	  document.Kontaktformular.Name.focus();
	  message.style.display = "block";
	  return false;
	}
	if (document.Kontaktformular.Mail.value == "") {
	  document.Kontaktformular.Mail.focus();
	  message.style.display = "block";
	  return false;
	}
	/* if (document.Kontaktformular.Mail.value.indexOf("@") == -1) {
	  document.Kontaktformular.Mail.focus();
	  message = document.getElementById("wrong_email");
	  message.style.display = "block";
	  return false;
	} */
}