Help with updating the grid(CONNECT 4)

Question

Hi, this a small portion of my connect 4 game program. I have a problem with updating the grid. During the game, whenever I enter a column number for the first time, the program works properly. But when i try to give the same column for the second time, the chip falls in the same row instead of going to the second row. Can anybody help me write the method that will do this.
This is the method that switches the chip's value(By the way discard the variable 'turn' because that works properly, it is used in another method):
    //Method 2: Updates the matrix
    public static void UpdateMatrix (char location, char turn)
        c.println (location);
        switch (location)
            case '1':
                matrix [5] [0] = turn;
                break;
            case '2':
                matrix [5] [1] = turn;
                break;
            case '3':
                matrix [5] [2] = turn;
                break;
            case '4':
                matrix [5] [3] = turn;
                break;
            case '5':
                matrix [5] [4] = turn;
                break;
            case '6':
                matrix [5] [5] = turn;
                break;
            case '7':
                matrix [5] [6] = turn;
                break;
    } //End Method 2Can anybody describe me how to write a method or write a method that will tell the computer to assign the chip to the next row. You an edit my method if u want to. THANX A LOT!!!

Answer 1

HERE IS THE METHODS SO FAR!
    //Method 3: Checks if assigned place for the chip has a chip there already
    public static void emptyspot (int column, int row)
        for (row = 5 ; row >= 0 ; row--)
            for (column = 0 ; column <= 6 ; column++)
                if (matrix [row] [column] == 'X' || matrix [row] [column] == 'O')
                    row--;
    }I AM GETTING AN ERROR!!! AT THE BOTTOM OF MY PROGRAM! SOMEBODY HELP!
Message was edited by:
Taufiq