public static int[] get_av_students() {
    int av_students[] = new int[9];
    for(int i = 0; i < 9; i++)
    {
      int hour = (10 + i)%12;
      if ( hour == 0 ) {
        hour = 12;
      }
  while (true){
        try{
          av_students[i] = Integer.parseInt(JOptionPane.showInputDialog(null, "Average Students "+hour+":00"));
          if (av_students[i] < 0) {
            JOptionPane.showMessageDialog(null,"No Negative Entries");
            continue;
          }
        }
        catch (IllegalArgumentException e) {
          JOptionPane.showMessageDialog(null,"Entries Must Be Numbers");
          continue;
        }
        break;
      }
      av_students[i] = Integer.parseInt(JOptionPane.showInputDialog(null, "Average Students "+hour+":00"));

    }catch (IllegalArgumentException ex) {
         JOptionPane.showMessageDialog(null, " NO NEGETIVES ALLOWED ");
         }
         return av_students;
  }