function number_format (number, decimals, dec_point, thousands_sep)
	{
	/* ----------------------------------------------------
		Beispiele:
		number_format (1, 2, ",") = "1,00"
		number_format (1.2, null, ",") = "1,2"
		number_format (1234, 0, null, ".") = "1.234"
		number_format (1.23456e50, 4, ",") = "1,2346e+50"
		number_format (-950.5, 2, ",", ".") = "-950,50"
		number_format (-0.5, 2, ",") = "-0,50"
		number_format (-0.001, 2, ",") = "0,00"
	  ---------------------------------------------------- */
	  var exponent = "";
	  var numberstr = number.toString ();
	  var eindex = numberstr.indexOf ("e");
	  if (eindex > -1)
	  {
	    exponent = numberstr.substring (eindex);
	    number = parseFloat (numberstr.substring (0, eindex));
	  }
	  
	  if (decimals != null)
	  {
	    var temp = Math.pow (10, decimals);
	    number = Math.round (number * temp) / temp;
	  }
	  var sign = number < 0 ? "-" : "";
	  var integer = (number > 0 ? 
	      Math.floor (number) : Math.abs (Math.ceil (number))).toString ();
	  
	  var fractional = number.toString ().substring (integer.length + sign.length);
	  dec_point = dec_point != null ? dec_point : ".";
	  fractional = decimals != null && decimals > 0 || fractional.length > 1 ? 
	               (dec_point + fractional.substring (1)) : "";
	  if (decimals != null && decimals > 0)
	  {
	    for (i = fractional.length - 1, z = decimals; i < z; ++i)
	      fractional += "0";
	  }
	  
	  thousands_sep = (thousands_sep != dec_point || fractional.length == 0) ? 
	                  thousands_sep : null;
	  if (thousands_sep != null && thousands_sep != "")
	  {
		for (i = integer.length - 3; i > 0; i -= 3)
	      integer = integer.substring (0 , i) + thousands_sep + integer.substring (i);
	  }
	  
	  return sign + integer + fractional + exponent;
	}