double IsDigits(char *char_num)
{
	double num;
	int i = 0, flag = 0;
	while (char_num[i] != '\0')
	{
		if ((char_num[i] < '0' || char_num[i] > '9') && char_num[i] != ',')
			return 0.0;
		if (char_num[i] == ',')
		{
			flag++;
				if (flag > 1)
					return 0.0;
		}
		i++;
	}