Help array losing data

I have a 2 dimensional array in void start.
Basically its;
declared at the top of the class:

public int[,] everynumber;

And then, in start.

int[,] everynumber = new int[31,140];

Then I assign a number to everynumber[x,y] with fornext loops.
I then print (everynumber[2,2]); in start, and it returns the value 1, which is correct.
But when I attempt to use everynumber[2,2] in Update, I get a NullReferenceException.

Somewhere between Start and Update my array is losing all its values, how do I prevent this? What am I missing?

If you start a statement with the type like you do in Start : int[,] everynumber = new int[31,140]; you are declaring a new array. Leave out the int[,] and you will assign to the array created at the top of the class.