Trouble calling a method...

Question

I'm writing a stat roller program for my java class, but I'm having a slight problem. I have a combo box panel object, and the Roll object which I am trying to work with. When I try to call the method to assign a value to my array, is says...
"Cannot make a static reference to a non-static method getRoll() from the type Roll()"
Here is the code from the 2 objects...
First the Combo Box Panel Object..
package StatRoller;
import java.awt.GridLayout;
import java.util.Random;
import javax.swing.JComboBox;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class StatBoxPanel extends JPanel
     private static final long serialVersionUID = 1L;
     private int STAT_NUM = 5;
     private int[] stat1 = new int[STAT_NUM];
     private JComboBox strBox;
     private JComboBox dexBox;
     private JComboBox conBox;
     private JComboBox intelBox;
     private JComboBox wisBox;
     private JComboBox chaBox;
     public StatBoxPanel()
          stat1[0] = Roll.getRoll();
          setLayout(new GridLayout(6,1));
          strBox = new JComboBox();
          dexBox = new JComboBox();
          conBox = new JComboBox();
          intelBox = new JComboBox();
          wisBox = new JComboBox();
          chaBox = new JComboBox();
          add(strBox);
          add(dexBox);
          add(conBox);
          add(intelBox);
          add(wisBox);
          add(chaBox);
     public int modBox()
}and the Roll object...
package StatRoller;
import java.util.Random;
public class Roll
     int ROLL_NUM = 3;
     Random roll = new Random();
     int[] str = new int[ROLL_NUM];
     public Roll()
          str[0] = roll.nextInt(6);
          str[1] = roll.nextInt(6);
          str[2] = roll.nextInt(6);
          str[3] = roll.nextInt(6);
          for(int i = 0; str[i] <= 0; i++)
               str[i] = roll.nextInt(6);
          selectionSort(str);
     public int getRoll()
          int total = 0;
          total = str[1] + str[2] + str[3];
          return total;
     public static void selectionSort(int[] array)
          int startScan, index, minIndex, minValue;
          for (startScan = 0; startScan < (array.length-1); startScan++)
               minIndex = startScan;
               minValue = array[startScan];
               for(index = startScan + 1; index < array.length; index++)
                    if(array[index] < minValue)
                         minValue = array[index];
                         minIndex = index;
               array[minIndex] = array[startScan];
               array[startScan] = minValue;
}I need to know why when I call getRoll, I can't assign the value it returns to the stat1 array in the Combo Box Panel object.

Answer 1

All I'm trying to do now is get away from the combo boxes. What I've decided I want to do is use Radio Buttons, so that when they are selected they call getRoll, and set the text of a TextField to the number getRoll generates.
Yet, I still can't get away from making a static reference to a non-static method. Any suggestions?
I could really use some help.
Thanks.