diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 938bcea..e993d63 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -18,10 +18,7 @@
         <activity
             android:name="tu_darmstadt.sudoku.ui.SettingsActivity"
             android:label="@string/title_activity_settings"
-            android:parentActivityName="tu_darmstadt.sudoku.ui.MainActivity" >
-            <meta-data
-                android:name="android.support.PARENT_ACTIVITY"
-                android:value="tu_darmstadt.sudoku.ui.MainActivity" />
+            android:parentActivityName="tu_darmstadt.sudoku.ui.MainActivity">
         </activity>
         <activity
             android:name="tu_darmstadt.sudoku.ui.GameActivity"
diff --git a/app/src/main/java/tu_darmstadt/sudoku/controller/GameController.java b/app/src/main/java/tu_darmstadt/sudoku/controller/GameController.java
index 073d851..ad7c7de 100644
--- a/app/src/main/java/tu_darmstadt/sudoku/controller/GameController.java
+++ b/app/src/main/java/tu_darmstadt/sudoku/controller/GameController.java
@@ -63,14 +63,24 @@ public class GameController {
         this.sectionHeight = sectionHeight;
         this.sectionWidth = sectionWidth;
         this.gameField = new GameField(size, sectionHeight, sectionWidth);
+
+        if(fixedValues == null) throw new IllegalArgumentException("fixedValues may not be null.");
+
         gameField.initCells(fixedValues);
 
         // now set the values that are not fixed
-        for(int i = 0; i < size*size; i++) {
-            int row = (int)Math.floor(i/size);
-            int col = i%size;
-            setValue(row, col, setValues[i]);
+        if (setValues != null) {
+            for (int i = 0; i < size * size; i++) {
+                int row = (int) Math.floor(i / size);
+                int col = i % size;
+                setValue(row, col, setValues[i]);
+            }
         }
+
+        if(setNotes != null) {
+            // set notes.
+        }
+
     }
 
     public void setSettings(SharedPreferences pref) {
@@ -129,7 +139,7 @@ public class GameController {
     /** Use with care.
      */
     public GameCell getGameCell(int row, int col) {
-        return gameField.getCell(row,col);
+        return gameField.getCell(row, col);
     }
 
     public boolean isSolved() {
@@ -240,13 +250,36 @@ public class GameController {
         return gameField.toString();
     }
 
+    public int getSelectedRow() {
+        return selectedRow;
+    }
+
+    public int getSelectedCol() {
+        return selectedCol;
+    }
+
     public void selectCell(int row, int col) {
-        this.selectedRow = row;
-        this.selectedCol = col;
+        if(selectedRow == row && selectedCol == col) {
+            // if we select the same field 2ce -> deselect it
+            selectedRow = -1;
+            selectedCol = -1;
+        } else {
+            // else we set it to the new selected field
+            selectedRow = row;
+            selectedCol = col;
+        }
     }
 
     public void setSelectedValue(int value) {
-        setValue(selectedRow, selectedCol, value);
+        if(selectedRow != -1 && selectedCol != -1) setValue(selectedRow, selectedCol, value);
+    }
+
+    public void deleteSelectedValue() {
+        if(selectedRow != -1 && selectedCol != -1) setValue(selectedRow, selectedCol, 0);
+    }
+
+    public void toggleSelectedNote(int value) {
+        if(selectedRow != -1 && selectedCol != -1) toggleNote(selectedRow, selectedCol, value);
     }
 
 //    public void registerListener(IModelChangeListener l) {
diff --git a/app/src/main/java/tu_darmstadt/sudoku/game/GameField.java b/app/src/main/java/tu_darmstadt/sudoku/game/GameField.java
index 7b1ddeb..a7a12d7 100644
--- a/app/src/main/java/tu_darmstadt/sudoku/game/GameField.java
+++ b/app/src/main/java/tu_darmstadt/sudoku/game/GameField.java
@@ -51,14 +51,16 @@ public class GameField implements Cloneable {
                 { 7, 0, 0,  0, 1, 0,  3, 0, 5 }};
 
         // Initit the game field
+        int[] oneDimension = new int[size*size];
         for(int i = 0; i < size; i++) {
             for(int j = 0; j < size; j++) {
-                field[i][j] = new GameCell(i,j,size,placeholder[i][j]);
+                oneDimension[i*size+j] = placeholder[i][j];
             }
         }
     }
 
     public void initCells(int[] level) {
+        int count = 0;
         if(level.length != size*size) {
             throw new IllegalArgumentException("Levelarray must have length of "+size*size+".");
         }
@@ -66,8 +68,10 @@ public class GameField implements Cloneable {
         for(int i = 0; i < size*size; i++) {
             int row = (int)Math.floor(i/size);
             int col = i%size;
+            if(level[i] != 0) count++;
             field[row][col] = new GameCell(row,col,size,level[i]);
         }
+        if(count < 17) throw new IllegalArgumentException("There must be at least 17 fixed values.");
     }
 
     public GameCell getCell(int row, int col) {
diff --git a/app/src/main/java/tu_darmstadt/sudoku/ui/view/SudokuFieldLayout.java b/app/src/main/java/tu_darmstadt/sudoku/ui/view/SudokuFieldLayout.java
index cefd49d..9807264 100644
--- a/app/src/main/java/tu_darmstadt/sudoku/ui/view/SudokuFieldLayout.java
+++ b/app/src/main/java/tu_darmstadt/sudoku/ui/view/SudokuFieldLayout.java
@@ -53,12 +53,22 @@ public class SudokuFieldLayout extends RelativeLayout {
                     int row = scv.getRow();
                     int col = scv.getCol();
 
+                    gameController.selectCell(row, col);
+                    row = gameController.getSelectedRow();
+                    col = gameController.getSelectedCol();
+
                     // Reset everything
                     for(int i = 0; i < gameController.getSize(); i++) {
                         for(int j = 0; j < gameController.getSize(); j++) {
                             gamecells[i][j].setHighlightType(CellHighlightTypes.Default);
                         }
                     }
+
+                    if(row == -1 || col == -1) {
+                        // we clicked on the same cell 2 times.
+                        // means it got deselected and we dont highlight any cells.
+                        return false;
+                    }
                     // Set connected Fields
 
                     //String syncConnPref = sharedPref.getString(SettingsActivity., "");
@@ -70,7 +80,6 @@ public class SudokuFieldLayout extends RelativeLayout {
                         gamecells[c.getRow()][c.getCol()].setHighlightType(CellHighlightTypes.Connected);
                     }
                     // Select touched Cell
-                    gameController.selectCell(row, col);
                     scv.setHighlightType(CellHighlightTypes.Selected);
 
 
diff --git a/app/src/test/java/tu_darmstadt/sudoku/game/solver/SolverTest.java b/app/src/test/java/tu_darmstadt/sudoku/game/solver/SolverTest.java
index 9745627..1217f11 100644
--- a/app/src/test/java/tu_darmstadt/sudoku/game/solver/SolverTest.java
+++ b/app/src/test/java/tu_darmstadt/sudoku/game/solver/SolverTest.java
@@ -26,6 +26,8 @@ public class SolverTest {
                 { 0, 0, 0,  0, 7, 0,  4, 0, 9 },
                 { 6, 4, 0,  0, 0, 0,  0, 0, 0 },
                 { 7, 0, 0,  0, 1, 0,  3, 0, 5 }};
+
+        controller.loadLevel(9,3,3,new int[]{0,0,0,0,4,1,0,0,0,0,6,0,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0,3,2,0,6,0,0,0,0,0,0,0,0,0,5,0,0,4,1,7,0,0,0,0,0,0,0,0,0,0,0,2,0,0,3,0,0,0,4,8,0,0,0,0,0,0,5,0,1,0,0,0,0,0,0},null,null);
     }
 
     //000041000060000200000000000320600000000050041700000000000200300048000000501000000