function checkRequiredFields(input)
{

    var requiredFields = new Array("name",
                                   "adresse",
                                   "ort",
                                   "email");

    var fieldNames = new Array("Name",
                               "Adresse",
                               "PLZ/Ort",
                               "E-Mail");
    var fieldCheck   = true;
    var fieldsNeeded = "\nIn diesem Formular m%FCssen Sie alle mit * gekennzeichneten Felder ausf%FCllen! Bitte\nF%FCllen Sie folgende noch leere Felder aus:\n\n\t";

    for(var fieldNum=0; fieldNum < requiredFields.length; fieldNum++) {
        if ((input.elements[requiredFields[fieldNum]].value == "") ||
            (input.elements[requiredFields[fieldNum]].value == " ")) {

            fieldsNeeded += fieldNames[fieldNum] + "\n\t";
            fieldCheck = false;
        }
    }

    if (fieldCheck == true)
    {
        return true;
    }
    else
    {
        alert(unescape(fieldsNeeded));
        return false;
    }
}