Toggle Boolean Values in Multidimensional Array

I am trying to get this method to be able to toggle between false and true for my 2 dimensional boolean array. Each value in the array corresponds to a square, but I need to toggle between the two whenever a certain square with coordinates row and column is pushed within the window. However, it is giving me an error for invalid operator == so I am not sure how else to go about this. Any help would be appreciated.

public void clickSquare( int row, int column ) 
        {

             if (grid[row][column] == false)
             {
                 grid[row][column] == true;  
             }
             else
             {
                 grid[row][column] == false; 
             }
            return;  
        }