Error with JDK 1.3.1_02

Question

Can anyone help with this somple problem. I have just downloaded JDK 2 1.3.1_02 and run a simple input program with the latest version of JDK Commander.
The following error keeps coming up in regards to Course_io:
Heres the program and beneath is the error that keeps coming up when javac is run.
/*program that reads in grades and then displays the total amount of
pupils with those grades*/
import java.io.*;
class Excercise_4_3
     public static void main(String[]args)
          throws IOException
     int grade_1_count=0, grade_2_count=0,grade;
     System.out.println("Input the Grade or negative number or 0 to termintate");
     grade=Course_io.readInt();
     while(grade>=1)
          if(grade==2)
               grade_2_count=grade_2_count+1;
          else if(grade==1)
               grade_1_count=grade_1_count+1;
          else if(grade>2)
               System.out.println("You can only enter grade 1 or 2");
          else
               grade_1_count=grade_1_count+0;
               grade_2_count=grade_2_count+0;
               System.out.println("Enter a grade or negative number or 0 to terminate");
               grade=Course_io.readInt();
          System.out.println("Number of pupils with grade 1 are "
                         +grade_1_count);
          System.out.println("Number of pupils with grade 2 are "
                         +grade_2_count);
Heres the error when Javac is run:
I think that the problem is that Course_io is not been imported when import java_io*;is commanded.
I have tried executing the JDK commander with different folders from the JDK 2 1.3.1_02 but no luck there.
javac -d . -g "C:\Java Pracs\Excercise_4_3.java"
C:\Java Pracs\Excercise_4_3.java:11: cannot resolve symbol
symbol : variable Course_io
location: class Excercise_4_3
     grade=Course_io.readInt();
^
C:\Java Pracs\Excercise_4_3.java:33: cannot resolve symbol
symbol : variable Course_io
location: class Excercise_4_3
               grade=Course_io.readInt();
^
2 errors
Some help will be really appreciated.
Thanks
G Engelbrecht

Answer 1

1. Is Course_io a class in the same directory as the other source file
2. if yes then is readInt() a static method of the class Course_io. If not then u need to create an instance of Course_io and then call readInt() on it.
3. Could u please post the structure of the other class file.
Plz format u'r src before posting. Makes our lives easier
:-)