var f0 = "Bitte überprüfen Sie Ihre Eingaben:\n";
var f1 = "  - Bitte wählen Sie einen Zulassungsbezirk aus!\n";

var f3 = "  - Bitte geben Sie den Zulassungsbezirk an, über den Sie informiert werden wollen, wenn dieser eingestellt wird!\n";
var f4 = "  - Bitte geben Sie eine gültige E-Mail-Adresse an!\n";

function checkFormChoose(form) {
    var errorMessage = "";
    if (form.zulassungsbezirk.selectedIndex==0) {
        errorMessage += f1;
    }
    if (errorMessage!="") {
        errorMessage = f0 + errorMessage;
        alert(errorMessage);
        return false;
    } else {
        return true;
    }
}

function checkFormMail(form) {
    var errorMessage = "";
    if (form.zulassungsbezirk.value=="") {
        errorMessage += f3;
    }
    if ( (form.email.value=="") || !checkEmail(form.email.value) ) {
        errorMessage += f4;
    }
    if (errorMessage!="") {
        errorMessage = f0 + errorMessage;
        alert(errorMessage);
        return false;
    } else {
        return true;
    }
}

function checkEmail(email) {
    var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9])+$/;
    return filter.test(email);
}







var pop = null;
function popupFenster(obj, width, height) {
    var url = (obj.getAttribute) ? obj.getAttribute('href') : obj.href;
    if (!url) {
        return true;
    }
    // 400px*400px is the default size
    var popupWidth  = (width) ? width : 400;
    var popupHeight = (height) ? height : 400;
    // Centering of the popup window
    var xPos = Math.round((screen.width - popupWidth) / 2);
    var yPos = Math.round((screen.height - popupHeight) / 2);
    var params = "width=" + popupWidth + ",height=" + popupHeight;
    params += ",left=" + xPos + ",top=" + yPos;
    params += ",scrollbars=yes,status=no,toolbar=no,resizable";
    if (pop && !pop.closed) {
        pop.close();
    }
    pop = window.open(url,'fenster',params);
    if (pop) {
        pop.focus();
        return false;
    } else {
        return true;
    }
}

function getObject(id) {
    var element;
    if (document.all) {
        element = document.all(id);
    } else if (document.getElementById) {
        element = document.getElementById(id);
    }
    return element;
}

function dynWrite(id, text) {
    var obj = getObject(id);
    obj.innerHTML = text;
}


function checkDate(dateString) {
    var validDateFormat = /([0-9]{2})\.([0-9]{2})\.([0-9]{4})/;
    var result = validDateFormat.test(dateString);
    if (!result) {
        return false
    } else {
        var result = validDateFormat.exec(dateString);
        var day = RegExp.$1*1;
        var month = RegExp.$2*1;
        var year =  RegExp.$3*1;
        var days = Array(0,31,29,31,30,31,30,31,31,30,31,30,31);
        if ( isNaN(day) || isNaN(month) || isNaN(year) || (month<1) || (month>12) || (day>days[month]) ||
                ((day==29) && (month==2) && (!((year % 4 == 0) && ((year % 100 != 0) || (year % 400 == 0))))) ) {
            return false;
        } else {
            return true;
        }
    }
}