diff --git a/src/main/java/dotsandboxes/DotsAndBoxesGrid.java b/src/main/java/dotsandboxes/DotsAndBoxesGrid.java
index 32667af6c63a0287bd4f91c37682acb30c08e9a4..6a6f914ba774fa530f9a2714791c686d67608d9e 100644
--- a/src/main/java/dotsandboxes/DotsAndBoxesGrid.java
+++ b/src/main/java/dotsandboxes/DotsAndBoxesGrid.java
@@ -107,13 +107,16 @@ public class DotsAndBoxesGrid {
      * @return true if all four sides have been drawn.
      */
     public boolean boxComplete(int x, int y) {
+        System.out.println(x +" , "+ y);
         if (x >= width - 1 || x < 0 || y >= height - 1 || y < 0) {
             return false;
         }
+        else if (this.horizontals[x][y] && this.verticals[x][y]) {
+            // A box is complete if the north and south horizontals and the east and west verticals have all been drawn.
+            return true;
+        }
 
-        // A box is complete if the north and south horizontals and the east and west verticals have all been drawn.
-        // FIXME: You'll need to fix this code (after writing a test first).
-        return true;
+        return false;
     }
 
     /** Tries to claim a box for a player. If the box is complete, sets the ownership and returns true. */
@@ -139,10 +142,11 @@ public class DotsAndBoxesGrid {
         if (y >= height || y < 0) {
             throw new IndexOutOfBoundsException(String.format("y was %d, which is out of range. Range is 0 to %d", y, height));
         }
-
-        // FIXME: You need to throw an exception if the line was already drawn.
-
-        this.horizontals[x][y] = true;
+        if (this.horizontals[x][y]) {
+            throw new IllegalStateException(String.format("this line has already been selected"));
+        } else {
+            this.horizontals[x][y] = true;
+        }
 
         // Try to claim the north or south boxes
         boolean claimN = claimBox(x, y-1, player);
@@ -170,10 +174,12 @@ public class DotsAndBoxesGrid {
         if (y >= height - 1 || y < 0) {
             throw new IndexOutOfBoundsException(String.format("y was %d, which is out of range. Range is 0 to %d", y, height - 1));
         }
+        if (this.verticals[x][y]) {
+            throw new IllegalStateException(String.format("this line has already been selected"));
+        } else {
+            this.verticals[x][y] = true;
+        }
 
-        // You need to throw an exception if the line was already drawn.
-
-        this.verticals[x][y] = true;
         // Try to claim the north or south boxes
         boolean claimE = claimBox(x, y, player);
         boolean claimW = claimBox(x-1, y, player);