System.NullReferenceException c#

Question

I got data from the txt file, but I can't write to the 2D array .

public Form1()
{
    InitializeComponent();
}
public char[][] values;

This is my array description. I want to check data letter by letter.

string s = System.IO.File.ReadAllText(@textBox1.Text.ToString());
// Console.WriteLine(txtfile); 
string txtfile = s.Replace("\n","");

char[] numbers=txtfile.ToCharArray();

int i, j,p=0;
for (i=0;i<sayilar.Length;i++)
{

    Console.WriteLine(numbers[i]);
}
Console.WriteLine(numbers.Length);

for (i=0;i<9;i++)
 {
     for(j=0;j<9;j++)
     {

        values[i][j] = numbers[p];
         p++;
     }
 }

Wen I try run this I get the error System.NullReferenceException How can I fix this?