diff --git a/Chapter_10/Problem$09/Course.java b/Chapter_10/Problem$09/Course.java
index 0d47e50..efc3e9a 100644
--- a/Chapter_10/Problem$09/Course.java
+++ b/Chapter_10/Problem$09/Course.java
@@ -50,16 +50,17 @@ public void clear()
     }
 
 
-    public void dropStudent(String studentName)
+   public void dropStudent(String studentName)
     {
         boolean reach = false;
-        for (int i = 0; i < numberOfStudents+1;i++)
-        {
+        for (int i = 0; i <= numberOfStudents-1;i++) {
             if (!reach)
                 if (students[i].equals(studentName))
                     reach = true;
+
             if (reach)
-                students[i] = students[i+1];
+                if (i < numberOfStudents - 1)
+                    students[i] = students[i + 1];
         }
         numberOfStudents--;
     }