Selection problem !!!

Question

Hi. I have this code:

using System;

class Selection
{
  public static void SelectionSort(ref int[] T)
  {
 int min = 0, i, j, pom;
 for (i = 0; i < (T.Length-1); i++)
 {
   min = i;
   for (j = i + 1; j < T.Length; j++)
   {
  if (T[j] < T[min])
    min = j;
   }
   pom = T[i];
   T[i] = T[min];
   T[min] = pom;
 }
  }
  public static void InsertionSort(ref int[] T)
  {
 int j, pom;
 for (int i = 1; i < T.Length; i++)
 {
   j = i;
   pom = T[i];
   while (T[j-1] > pom)
   {
  T[j] = T[j-1];
  j = j-1;
   }
   T[j] = pom;
 }
  }
  public static void BubbelSort(ref int[] T)
  {
 int pom;
 for (int i = 1; i < T.Length; i++)
   for (int j = T.Length; j > i; j--)
  if (T[j-1] > T[j])
  {
    pom = T[j-1];
    T[j-1] = T[j];
    T[j] = pom;
  }
  }

  public static void Main()
  {
 Console.Write("Podaj liczbe el. tablicy: ");
 int n = Int32.Parse(Console.ReadLine());
 int[] tab = new int[n];
 Random rnd = new Random();
 for (int i = 0; i < tab.Length; i++)
 {
   tab[i] = rnd.Next(10);
   Console.WriteLine(tab[i]);
 }
 Console.WriteLine();
 BubbelSort(ref tab);
 for (int i = 0; i < tab.Length; i++)
 Console.WriteLine(tab[i]);
 Console.ReadLine();
  }
}

And when i am using BubbelSort and InsertionSort program shows exception System.IndexOutOfRangeException, and my question sounds why ?? (SelectionSort works good)