Descending Sort

/*
 * Sort 3 real values in descending order using nested if statements.
*/

using System;

class DescendingSort
{
    static void Main()
    {
        double number1, number2, number3, biggestNumber, middleNumber, smallestNumber;
        string invalidInput = "Please enter a value between " + double.MinValue + " and " + double.MaxValue + Environment.NewLine;
        bool equal;

        do
        {
            Console.WriteLine("Enter three different integer numbers!" + Environment.NewLine);
            Console.WriteLine("Enter value of number1: ");
            while (!(double.TryParse(Console.ReadLine(), out number1) && number1 >= double.MinValue && number1 <= double.MaxValue))
            {
                Console.WriteLine(invalidInput);
                Console.WriteLine("Enter value of number1: ");
            }

            Console.WriteLine("Enter value of number2: ");
            while (!(double.TryParse(Console.ReadLine(), out number2) && (number2 >= double.MinValue) && (number2 <= double.MaxValue)))
            {
                Console.WriteLine(invalidInput);
                Console.WriteLine("Enter value of number2: ");
            }

            Console.WriteLine("Enter value of number3: ");
            while (!(double.TryParse(Console.ReadLine(), out number3) && (number3 >= double.MinValue) && (number3 <= double.MaxValue)))
            {
                Console.WriteLine(invalidInput);
                Console.WriteLine("Enter value of number3: ");
            }
            if (number1 == number2 || number1 == number3 || number2 == number3)
            {
                equal = true;
            }
            else
            {
                equal = false;
            }
            Console.WriteLine();
        } while (equal);

        bool checkNumber1 = number1 > number2 && number1 > number3;
        bool checkNumber2 = number2 > number1 && number2 > number3;

        if (checkNumber1)
        {
            biggestNumber = number1;
            if(number2 > number3)
            {
                middleNumber = number2;
                smallestNumber = number3;
            }
            else
            {
                middleNumber = number3;
                smallestNumber = number2;
            }
        }
        else if (checkNumber2)
        {
            biggestNumber = number2;
            if (number1 > number3)
            {
                middleNumber = number1;
                smallestNumber = number3;
            }
            else
            {
                middleNumber = number3;
                smallestNumber = number1;
            }
        }
        else
        {
            biggestNumber = number3;
            if (number1 > number2)
            {
                middleNumber = number1;
                smallestNumber = number2;
            }
            else
            {
                middleNumber = number2;
                smallestNumber = number1;
            }
        }
        number1 = biggestNumber;
        number2 = middleNumber;
        number3 = smallestNumber;

        Console.WriteLine();
        Console.WriteLine("Descending sort: {0}, {1}, {2}!" + Environment.NewLine, number1, number2, number3);
        Main();
    }
}