Chances are you're using a culture which doesn't use "." as the
decimal separator.

Try specifying CultureInfo.InvariantCulture as the culture in the
Convert.ToDouble call.

Jon

The ToDouble method is using a NumberFormat object that specifies
different characters for decimal separator and thousands separator than
what you have in the string.

The method uses the NumberFormat of the CultureInfo.CurrentCulture object.

You can use the Double.Parse method instead, so that you can specify the
 FormatInfo or CultureInfo object directly. For a string that uses a
period as decimal separator, you can use the InvariantCulture object:

string s = "2.1415926536";
double d = double.Parse(s, CultureInfo.InvariantCulture);

I found what was the problem.
I was using "," as decimal point instad of "."
Isn't this function should work OK if I am using "," as decimal point ??