Problem getting program to run correctly

Question

I have an assignment where I need to write a program inputting test scores and outputting the minimum, maximum, and average scores. The program runs, but I cant get the min and max scores right. Also, pressing 999 doesn't force the program to quit.
Here is what I have...
import java.util.Scanner; //For scanner class
import java.text.DecimalFormat;
public class Testscores
{ public static void main (String [] args)
     {//instructions
     System.out.println("Enter test scores, and get the lowest score, the highest score, "
          + "and the average. ");
     System.out.println("Enter 999 to quit. ");
     //scanner
     Scanner kbd = new Scanner (System.in);
     //variables
     int score = 0;
     int total = 0;
     int count = 0;
     final int maxposs = 100;
     final int minposs = 0;
     int min = maxposs;
     int max = minposs;
     final int sentinel = 999;
     //input
     while (score >= 0)
     if (score <= 100 && score >=0)
     {System.out.print("Enter a score [0..100] (999 to quit): ");
     score = kbd.nextInt();
     total += score;
     count ++;
     else
     System.out.print(" Enter only 0..100 (999 to quit): ");
     score = kbd.nextInt();
     if (score < min && score > 0)
     {min = score;
     //output
     DecimalFormat formatter = new DecimalFormat ("#0.00");
     if (count >0) //genuine scores entered
     {System.out.println("The minimum score is " + min + "." );
     System.out.println("The maximum score is " + max + "." );
     float average = (float) total / (float) count;
     System.out.println("The average score is " + average + ".");

Answer 1

import java.util.Scanner;             //For scanner class
import java.text.DecimalFormat;
public class TRx
    public static void main (String [] args)
        //instructions
        System.out.println("Enter test scores, and get the lowest score, " +
                           "the highest score, and the average. ");
        System.out.println("Enter 999 to quit. ");
        //scanner
        Scanner kbd = new Scanner (System.in);
        //variables
        int score = 0;
        int total = 0;
        int count = 0;
        final int maxposs = 100;
        final int minposs = 0;
        int min = maxposs;
        int max = minposs;
        final int sentinel = 999;
        //input
        boolean morePlease = true;
        while (morePlease)
            System.out.print("Enter a score [0..100] (999 to quit): ");
            score = kbd.nextInt();
            if(score == sentinel)
                break;
            if(score < minposs || score > maxposs)
                System.out.print(" Enter only 0..100 (999 to quit): ");
                continue;
            if (score < min)
                min = score;
            if(score > max)
                max = score;
            total += score;
            count ++;
        //output
        DecimalFormat formatter = new DecimalFormat ("#0.00");
        if (count >0)                   //genuine scores entered
            System.out.println("The minimum score is " + min + "." );
            System.out.println("The maximum score is " + max + "." );
            float average = (float) total / (float) count;
            System.out.println("The average score is " + average + ".");
}