function checkRequiredFields(input){
    var requiredFields = new Array("name",
                                   "bild",
                                   "art_nr",
								   "system",
                                   "usk",
                                   "sys_vor",
                                   "sprache",
								   "preis",
				   "main_cat",			   "min_order_level",
				   "angebot",			   "offer_date",
				   "text");


    var fieldNames =  new Array("name",
                                   "bild",
                                   "art_nr",
								   "system",
                                   "usk",
                                   "sys_vor",
                                   "sprache",
								   "preis",
				   "main_cat",			   "min_order_level",
				   "angebot",			   "offer_date",
				   "text");
    var fieldCheck   = true;

    var fieldsNeeded = "\n Folgende Felder müssen ausgefüllt werden:\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(fieldsNeeded);
       return false;
    }
}