diff --git a/src/main/java/dotsandboxes/DotsAndBoxesGrid.java b/src/main/java/dotsandboxes/DotsAndBoxesGrid.java
index 4f774b198f230ca82e5cc94d51967846aa05d5f5..0ed2d670a69141259f178fcc794df895386da342 100644
--- a/src/main/java/dotsandboxes/DotsAndBoxesGrid.java
+++ b/src/main/java/dotsandboxes/DotsAndBoxesGrid.java
@@ -106,14 +106,18 @@ public class DotsAndBoxesGrid {
      * @param y coordinate of the top of the box
      * @return true if all four sides have been drawn.
      */
-    public boolean boxComplete(int x, int y) {
-        if (x >= width - 1 || x < 0 || y >= height - 1 || y < 0) {
-            return false;
-        }
+     public boolean boxComplete(int x, int y) {
+            if (x >= width - 1 || x < 0 || y >= height -1 || y < 0) {
+                return false;
+            }
+            if ((getHorizontal(x, y) && getHorizontal(x, y + 1) &&
+                getVertical(x, y) && getVertical(x + 1, y))) {
+                return true;
+            }
+            else
+            {
+                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;
     }
 
     /** Tries to claim a box for a player. If the box is complete, sets the ownership and returns true. */
@@ -140,7 +144,9 @@ public class DotsAndBoxesGrid {
             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.
+        if (getHorizontal(x, y)) {
+            throw new RuntimeException("Line already drawn.");
+        }
 
         this.horizontals[x][y] = true;
 
@@ -171,7 +177,9 @@ public class DotsAndBoxesGrid {
             throw new IndexOutOfBoundsException(String.format("y was %d, which is out of range. Range is 0 to %d", y, height - 1));
         }
 
-        // You need to throw an exception if the line was already drawn.
+        if (getVertical(x, y)) {
+            throw new RuntimeException("Line already drawn.");
+        }
 
         this.verticals[x][y] = true;
         // Try to claim the north or south boxes