problem with calculation

public class debgrader

{

public static void main(String[] args )

{

int numberofstudents,score;

double next;

char answer, grade;

do

{

System.out.println("Enter scores for all students");

System.out.println("Enter a negative numger after");

System.out.println("You have entered all the scores.");

numberofstudents = 0;

score = 0;

grade=0;

next = SavitchIn.readLineDouble();

while (next >=0)

{

numberofstudents++;

next = SavitchIn.readLineDouble();

}

if (numberofstudents > 0)

System.out.println("Total number of grades " + (numberofstudents));

{

numberofstudents = grade;

if (score >= 90){

grade ='A';

numberofstudents++;}

else if (score >= 80){

grade ='B';

numberofstudents++;}

else if (score >= 70){

grade ='C';

numberofstudents++;}

else if (score >= 60){

grade ='D';

numberofstudents++;}

else if (score < 60){

grade ='F';

numberofstudents++;}

}

System.out.println("Number of A's = " + (numberofstudents++));

System.out.println("Number of B's = " + (numberofstudents++));

System.out.println("Number of C's = "+ (numberofstudents++));

System.out.println("Number of D's = "+ (numberofstudents++));

System.out.println("Number of F's = "+ (numberofstudents++));

System.out.println("Want to score another exam?");

System.out.println("Enter y for yes or n for no.");

answer = SavitchIn.readLineNonwhiteChar();

}while ((answer == 'y') || (answer == 'Y'));

}

}

will not calculate the right number of letter grades

what am I doing wrong ?

please help Thank you.

[1826 byte] By [del] at [2007-9-30 22:29:38]