function Ersetzen(string, txt, by)
	{
	var strLength = string.length, txtLength = txt.length;

	if ((strLength == 0) || (txtLength == 0))
		{
		return string;
		}

	var i = string.indexOf(txt);

	if ((!i) && (txt != string.substring(0, (txtLength))))
		{
		return string;
		}

	if (i == -1)
		{
		return string;
		}

	var newstr = string.substring(0, (i)) + by;

	if (i + txtLength < strLength)
		{
		newstr += Ersetzen(string.substring(i + txtLength, strLength), txt, by);
		}

	return newstr;
	}