C#: Matrix with value zero changes corresponding row and column to zero

Aim: Change all the value of corresponding row and column to zero, if ever the matrix contains zero as one of the elements.

//declare variable to store start index containing value zero
int[] strtIndx;
//declare variable to store end index containing value zero
int[] endIndx ;
//variables as counters to make the corresponding row
//and column zero
int m = 0;
int n = 0;

//function to display matrix
public void DisplayMatrix(int[,] ary, int p, int q)
{
//Intialise start index and end index by matrix length
strtIndx = new int[ary.Length];
endIndx = new int[ary.Length];
 //loop through two dimensional array
for (int i = 0; i < p; i++)
{
   for (int j = 0; j < q; j++)
   {
    Console.Write(ary[i, j]);
    Console.Write("  ");
    }
 Console.WriteLine();
}
}
 //function to change the corresponding row and column to zero
public void matrix(int[,] ary, int p, int q)
{
strtIndx = new int[ary.Length];
endIndx = new int[ary.Length];
//p and q represents the dimension of array
for (int i = 0; i < p; i++)
{
   for (int j = 0; j < q;j++)
   {
// Check for each value is equal to zero or not
    if (ary[i, j] == 0)
    {
//if true, store the first index to startindex
//and second index of two dimensional array to endindex
     strtIndx[m] = i;
     endIndx[n] = j;
//Increment the counter
     m++;
     n++;
     }
  }
}

//reset the value to zero
m = 0;
n = 0;
//loop through all elements and check for index equal to startindex and endindex
for (int i = 0; i < p; i++)
{
  for (int j = 0; j < q; j++)
  {
   if (i == strtIndx[m])
   {
//true, then set the value of that particular index zero
    ary[i,j]=0;
    }
     if (j == endIndx[n])
     {
      ary[i, j] = 0;
      }
    }
}    

//Input Matrix as
 { { 1, 2 }, { 3,0 }, { 5, 6 } } and dimensions as 3X2

ie,   1    2
       3    0
       5    6

Output: 1    0
              0    0
              5    0