* The Java part should be fine (bug not free).

JudgeEngine.java

@@ -1,5 +1,6 @@
 import model.*;
 import jess.*;
+import java.util.Iterator;
 
 public class JudgeEngine {
     private Rete engine;
@@ -14,8 +15,40 @@ public JudgeEngine(SystemDatabase aDatabase) throws JessException {
 
         database = aDatabase;
         engine.addAll(database.getCourses());
-        engine.addAll(database.getStudents());
+        // engine.addAll(database.getStudents());
+
+        // loadCoursesData();
 
         marker = engine.mark();
     }
+    /*
+    private void loadCoursesData() throws JessException {
+        Courses courses = database.getCourses();
+
+        for (Iterator iter = courses.iterator(); iter.hasNext();) {
+            Course course = (Course) iter.next();
+            engine.add(course);
+        }
+    }
+    */
+
+    private void loadStudentsData(int sID) throws JessException {
+        Student student = database.getStudent(sID);
+
+        if (student != null) {
+            engine.add(student);
+            // engine.addAll(student.getCourseTaken());
+        }
+    }
+
+    private Iterator run(int sID, String cID, String secID) throws JessException {
+        engine.resetToMark(marker);
+
+        loadStudentsData(sID);
+        engine.add(new Register(sID, cID, secID));
+
+        engine.run();
+
+        return engine.getObjects(new Filter.ByClass(Decision.class));
+    }
 }

SystemDatabase.java

@@ -78,4 +78,8 @@ public Collection getStudents() {
     public String toString() {
         return courses.size() + "\n\n" + students.size();
     }
+
+    public Student getStudent(int sID) {
+        return (Student) students.get(new Integer(sID));
+    }
 }

model/Register.java

@@ -0,0 +1,13 @@
+package model;
+
+public class Register {
+    private int sID;
+    private String cID;
+    private String secID;
+
+    public Register(int sid, String cid, String secid) {
+        this.sID = sid;
+        this.cID = cid;
+        this.secID = secid;
+    }
+}

model/Student.java

@@ -27,4 +27,8 @@ public Student(int id, String name, String ctaken) {
 
         courseToTake = new Vector();
     }
+
+    public Vector getCoursesTaken() {
+        return courseTaken;
+    }
 }