function checkRequiredFields(input)
{
    var requiredFields = new Array("NAME",
                               "STRASSE",
                               "ORT",
                               "EMAIL");

    var fieldNames = new Array("Name:",
                                   "Strasse:",
                                   "Ort:",
                                   "E-Mail:");
    var fieldCheck   = true;
    var fieldsNeeded = "\nBitte\nFüllen Sie folgende Felder noch 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)
    {
    	if (input.elements["Bedingungen"].checked == false)
    	{
		alert("Bitte bestaetigen Sie, dass die Bedingungen des Veranstalters anerkannt werden.");
		return false;
		}
		else
		{
        return true;
        }
    }
    else
    {
        alert(fieldsNeeded);
        return false;
    }
}