function disableButtons(formIndex) {
	var form = document.forms[formIndex];
	var elements = form.getElementsByTagName('input');
	var len = elements.length;
	var oldElements = new Array(len);
	for (var i = 0; i < len; i++) {
		oldElements[i] = elements[i];
	}

	for (var i = 0; i < len; i++) {
		if (oldElements[i].getAttribute('type') != 'submit') 
			continue;

		dolly = oldElements[i].cloneNode(true);
		dolly.disabled = true;
		oldElements[i].parentNode.insertBefore(dolly, oldElements[i]);
		oldElements[i].style.display = "none";
	}
	
	window.setTimeout('enableButtons(' + formIndex + ')', 30*1000); //nach spätestens 30 Sekunden wieder freigeben
}

function enableButtons(formIndex) {
	var form = document.forms[formIndex];
	var len = form.elements.length;
	for (var i = 0; i < len; i++) {
		form.elements[i].disabled = false; 
	}
}

function addEvent(obj, evType, func, useCaption)
{
  if (obj.addEventListener) {
    obj.addEventListener(evType, func, useCaption);
    return true;
  } else if (obj.attachEvent) {
    var retVal = obj.attachEvent("on" + evType, func);
    return retVal;
  } else {
    return false;
  }
}

/*
function getEventTarget(e) {
	return (e.currentTarget ? e.currentTarget : event.srcElement);
}
*/

function onLoad() {
	if (document.forms)
	for (var i = 0; i < document.forms.length; i++) {
		addEvent(document.forms[i], 'submit', new Function('disableButtons(' + i + ')'), false);
	}
}

addEvent(window, 'load', onLoad, false);