diff --git a/CampusAppWP8/CampusAppWP8/Model/MainModel.cs b/CampusAppWP8/CampusAppWP8/Model/MainModel.cs
index ba793fda..ef64f4e2 100644
--- a/CampusAppWP8/CampusAppWP8/Model/MainModel.cs
+++ b/CampusAppWP8/CampusAppWP8/Model/MainModel.cs
@@ -172,6 +172,11 @@ namespace CampusAppWP8
         /// </summary>
         public event OnFailed onFailed = null;
 
+        /// <summary>
+        /// Callback pointer, called after failed saving data to file.
+        /// </summary>
+        public event OnFailed onFailedSave = null;
+
         /// <summary>
         /// Callback pointer, for checking if file is up to date at loading.
         /// </summary>
@@ -359,13 +364,30 @@ namespace CampusAppWP8
                 }
 
                 byte[] data = this.SerializeModel();
-                string test = Encoding.UTF8.GetString(data, 0, data.Length);
-                this.file.WriteFile(data);
 
+                if ((this.onSaved != null) && (this.onFailedSave != null))
+                {
+                    this.file.WriteFile(data, delegate() { this.onSaved(); }, delegate() { this.onFailedSave(); });
+                }
+                else if (this.onSaved != null)
+                {
+                    this.file.WriteFile(data, delegate() { this.onSaved(); }, null);
+                }
+                else if (this.onFailedSave != null)
+                {
+                    this.file.WriteFile(data, null, delegate() { this.onFailedSave(); });
+                }
+                else
+                {
+                    this.file.WriteFile(data, null, null);
+                }
+
+                /*
                 if (this.onSaved != null)
                 {
                     this.onSaved();
                 }
+                */
             }
         }
 
diff --git a/CampusAppWP8/CampusAppWP8/Utility/File.cs b/CampusAppWP8/CampusAppWP8/Utility/File.cs
index ae66a2e5..f03c9be8 100644
--- a/CampusAppWP8/CampusAppWP8/Utility/File.cs
+++ b/CampusAppWP8/CampusAppWP8/Utility/File.cs
@@ -9,6 +9,7 @@ namespace CampusAppWP8.Utility
 {
     using System;
     using System.IO;
+    using System.Threading;
     using Windows.Storage;
 
     /// <summary>
@@ -96,6 +97,11 @@ namespace CampusAppWP8.Utility
             ReadOnly = 3
         }
 
+        /// <summary>
+        /// Delegation of the write callback function prototype.
+        /// </summary>
+        public delegate void WriteCallbackFunc();
+
         /// <summary>
         /// Read data from file to a string.
         /// </summary>
@@ -133,24 +139,30 @@ namespace CampusAppWP8.Utility
         /// </summary>
         /// <param name="data">data byte array</param>
         /// <param name="ioType">write type</param>
-        public void WriteFile(byte[] data, IOTypeWrite ioType = IOTypeWrite.INVALID)
+        public void WriteFile(byte[] data, WriteCallbackFunc onSavedCallback, WriteCallbackFunc onFailedCallback, IOTypeWrite ioType = IOTypeWrite.INVALID)
         {
             IOTypeWrite tempType = ioType;
-
+           
             if (tempType == IOTypeWrite.INVALID)
             {
                 tempType = this.writeType;
             }
 
+            /*
             if (tempType == IOTypeWrite.WriteAsync)
             {
-                this.WriteAsync(data);
+                this.WriteAsync(data, onSavedCallback, onFailedCallback);
             }
             else if (tempType == IOTypeWrite.WriteSync)
             {
                 // this.WriteSync(data);
-                this.WriteAsync(data);
+                this.WriteAsync(data, onSavedCallback, onFailedCallback);
             }
+            */
+
+            Thread th = new Thread(delegate() { this.WriteAsync(data, onSavedCallback, onFailedCallback); });
+            th.Start();
+            //this.WriteAsync(data, onSavedCallback, onFailedCallback);
         }
 
         /// <summary>
@@ -218,14 +230,15 @@ namespace CampusAppWP8.Utility
         /// Write data asynchronous to file.
         /// </summary>
         /// <param name="data">data array</param>
-        private async void WriteAsync(byte[] data)
+        private async void WriteAsync(byte[] data, WriteCallbackFunc onSavedCallback, WriteCallbackFunc onFailedCallback)
         {
             Logger.LogMsg("writeasync file: " + this.filename);
             StorageFile file = null;
             Stream s = null;
+            int counter = 0;
 
             // try opening the file
-            while (file == null)
+            while ((file == null) && (counter < 10))
             {
                 try
                 {
@@ -233,12 +246,23 @@ namespace CampusAppWP8.Utility
                 }
                 catch (Exception)
                 {
+                    counter++;
                     System.Threading.Thread.Sleep(10);
                 }
             }
 
+            if (file == null)
+            {
+                if (onFailedCallback != null)
+                {
+                    onFailedCallback();
+                }
+                return;
+            }
+
+            counter = 0;
             // try to get a stream on the file
-            while (s == null)
+            while ((s == null) && (counter < 10))
             {
                 try
                 {
@@ -246,10 +270,20 @@ namespace CampusAppWP8.Utility
                 }
                 catch (Exception)
                 {
+                    counter++;
                     System.Threading.Thread.Sleep(10);
                 }
             }
 
+            if (s == null)
+            {
+                if (onFailedCallback != null)
+                {
+                    onFailedCallback();
+                }
+                return;
+            }
+
             // writing data
             try
             {
@@ -258,10 +292,21 @@ namespace CampusAppWP8.Utility
             }
             catch (Exception e)
             {
+                if (onFailedCallback != null)
+                {
+                    onFailedCallback();
+                }
                 Logger.LogException(e);
+                s.Dispose();
+                return;
             }
 
             s.Dispose();
+
+            if (onSavedCallback != null)
+            {
+                onSavedCallback();
+            }
         }
     }
 }
\ No newline at end of file