random array and system.tick (sorting algorithms)

// array of integers to hold values
private int[] a = new int[100];

// number of elements in array
private int x;

// Selection Sort Algorithm
public void sortArray()
{
  int i, j;
  int min, temp;

  for (i = 0; i < x - 1; i++)
  {
    min = i;

    for (j = i + 1; j < x; j++)
    {
      if (a[j] < a[min])
      {
        min = j;
      }
    }

    temp = a[i];
    a[i] = a[min];
    a[min] = temp;
  }
}

public static void Main()
{
  // Instantiate an instance of the class
  selectionSort mySort = new selectionSort();

  // Get the number of elements to store in the array
  Console.Write("Number of elements in the array (less than 100) : ");
  string s = Console.ReadLine();
  mySort.x = Int32.Parse(s);

  // Array header
  Console.WriteLine("");
  Console.WriteLine("-----------------------");
  Console.WriteLine(" Enter array elements  ");
  Console.WriteLine("-----------------------");

  // Get array elements
  for (int i = 0; i < mySort.x; i++)
  {
    Console.Write("<{0}> ", i + 1);
    string s1 = Console.ReadLine();
    mySort.a[i] = Int32.Parse(s1);
  }

  // Sort the array
  mySort.sortArray();

  // Output sorted array
  Console.WriteLine("");
  Console.WriteLine("-----------------------");
  Console.WriteLine(" Sorted array elements ");
  Console.WriteLine("-----------------------");

  for (int j = 0; j < mySort.x; j++)
  {
    Console.WriteLine(mySort.a[j]);
  }

  // Here to stop app from closing
  Console.WriteLine("\n\nPress Return to exit.");
  Console.Read();
}