public static int ConvertHexDigit(Char val)
{
if (val <= '9' && val >= '0')
return (val - '0');
else if (val >= 'a' && val <= 'f')
return ((val - 'a') + 10);
else if (val >= 'A' && val <= 'F')
return ((val - 'A') + 10);
else
throw new ArgumentException( Environment.GetResourceString( "ArgumentOutOfRange_Index" ) );
}