diff --git a/ENI2/ENI2.csproj b/ENI2/ENI2.csproj
index b9363d13..ec89f23c 100644
--- a/ENI2/ENI2.csproj
+++ b/ENI2/ENI2.csproj
@@ -228,6 +228,9 @@
     <Compile Include="Controls\LocodeControl.xaml.cs">
       <DependentUpon>LocodeControl.xaml</DependentUpon>
     </Compile>
+    <Compile Include="EditControls\CompareExcelDialog.xaml.cs">
+      <DependentUpon>CompareExcelDialog.xaml</DependentUpon>
+    </Compile>
     <Compile Include="EditControls\EditWasteReceiptDialog.xaml.cs">
       <DependentUpon>EditWasteReceiptDialog.xaml</DependentUpon>
     </Compile>
@@ -532,6 +535,10 @@
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
     </Page>
+    <Page Include="EditControls\CompareExcelDialog.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
     <Page Include="EditControls\CopyDeclarationDialog.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
@@ -777,10 +784,10 @@
     <None Include="Resources\lightbulb_on.png" />
     <None Include="Resources\rotate_left.png" />
     <Resource Include="Resources\sign_warning.png" />
-    <None Include="Resources\trafficlight_green.png" />
-    <None Include="Resources\trafficlight_off.png" />
-    <None Include="Resources\trafficlight_red.png" />
-    <None Include="Resources\trafficlight_yellow.png" />
+    <Resource Include="Resources\trafficlight_green.png" />
+    <Resource Include="Resources\trafficlight_off.png" />
+    <Resource Include="Resources\trafficlight_red.png" />
+    <Resource Include="Resources\trafficlight_yellow.png" />
     <None Include="Resources\user_edit.png" />
     <Resource Include="Resources\delete2.png" />
     <None Include="Resources\mail_new.png" />
diff --git a/ENI2/EditControls/CompareExcelDialog.xaml b/ENI2/EditControls/CompareExcelDialog.xaml
new file mode 100644
index 00000000..e8096095
--- /dev/null
+++ b/ENI2/EditControls/CompareExcelDialog.xaml
@@ -0,0 +1,35 @@
+<enictrl:StatusWindowBase x:Class="ENI2.EditControls.CompareExcelDialog"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        xmlns:local="clr-namespace:ENI2.EditControls"
+        xmlns:enictrl="clr-namespace:ENI2.Controls"        
+        xmlns:p="clr-namespace:ENI2.Properties"
+        xmlns:xctk="http://schemas.xceed.com/wpf/xaml/toolkit"
+        mc:Ignorable="d"
+        Title="{x:Static p:Resources.textCompareExcel}" Height="200" Width="600" Background="AliceBlue" Icon="/ENI2;component/Resources/bullet_ball_grey.ico">
+    <Grid>
+        <Grid.RowDefinitions>
+            <RowDefinition Height="60" />
+            <RowDefinition Height="60" />
+        </Grid.RowDefinitions>
+        <Grid.ColumnDefinitions>
+            <ColumnDefinition Width="80" />
+            <ColumnDefinition Width="60" />
+            <ColumnDefinition Width="*" />
+        </Grid.ColumnDefinitions>
+        <Label VerticalAlignment="Center" Grid.Row="0" Grid.Column="0">
+            <AccessText TextWrapping="Wrap">
+                First (original) sheet
+            </AccessText>
+        </Label>
+        <Image x:Name="imageSource" Grid.Row="0" Grid.Column="1" Margin="2" Source="../Resources/trafficlight_off.png" AllowDrop="True" Drop="imageSource_Drop" DragEnter="imageSource_DragEnter"/>
+        <Label VerticalAlignment="Center" Grid.Row="1" Grid.Column="0">
+            <AccessText TextWrapping="Wrap">
+                Second (updated) sheet
+            </AccessText>
+        </Label>
+        <Image x:Name="imageTarget" Grid.Row="1" Grid.Column="1" Margin="2"  Source="../Resources/trafficlight_off.png" AllowDrop="True" Drop="imageTarget_Drop" DragEnter="imageSource_DragEnter"/>
+    </Grid>
+</enictrl:StatusWindowBase>
diff --git a/ENI2/EditControls/CompareExcelDialog.xaml.cs b/ENI2/EditControls/CompareExcelDialog.xaml.cs
new file mode 100644
index 00000000..e60f774c
--- /dev/null
+++ b/ENI2/EditControls/CompareExcelDialog.xaml.cs
@@ -0,0 +1,78 @@
+using System;
+using System.IO;
+using System.Windows;
+using System.Windows.Media.Imaging;
+
+namespace ENI2.EditControls
+{
+    /// <summary>
+    /// Interaction logic for CompareExcelDialog.xaml
+    /// </summary>
+    public partial class CompareExcelDialog : Controls.StatusWindowBase
+    {
+        private string _sourcePath = null;
+        private string _targetPath = null;
+
+        public CompareExcelDialog()
+        {
+            InitializeComponent();
+        }
+
+        private void imageSource_Drop(object sender, DragEventArgs e)
+        {
+            string[] files = (string[]) e.Data.GetData(DataFormats.FileDrop);
+            foreach (string file in files)
+                Console.WriteLine(file);
+            if(files.Length > 0)
+            {
+                if(File.Exists(files[0]))
+                {
+                    if(files[0].EndsWith("xls") || files[0].EndsWith("xlsx"))
+                    {
+                        _sourcePath = files[0];
+                        imageSource.Source = new BitmapImage(new Uri("pack://application:,,,/Resources/trafficlight_green.png"));
+                    }
+                    else
+                    {
+                        imageSource.Source = new BitmapImage(new Uri("pack://application:,,,/Resources/trafficlight_yellow.png"));
+                    }
+                } 
+                else
+                {
+                    imageSource.Source = new BitmapImage(new Uri("pack://application:,,,/Resources/trafficlight_red.png"));
+                }
+            }
+        }
+
+        private void imageTarget_Drop(object sender, DragEventArgs e)
+        {
+            string[] files = (string[])e.Data.GetData(DataFormats.FileDrop);
+            foreach (string file in files)
+                Console.WriteLine(file);
+            if (files.Length > 0)
+            {
+                if (File.Exists(files[0]))
+                {
+                    if (files[0].EndsWith("xls") || files[0].EndsWith("xlsx"))
+                    {
+                        _targetPath = files[0];
+                        imageTarget.Source = new BitmapImage(new Uri("pack://application:,,,/Resources/trafficlight_green.png"));
+                    }
+                    else
+                    {
+                        imageTarget.Source = new BitmapImage(new Uri("pack://application:,,,/Resources/trafficlight_yellow.png"));
+                    }
+                }
+                else
+                {
+                    imageTarget.Source = new BitmapImage(new Uri("pack://application:,,,/Resources/trafficlight_red.png"));
+                }
+            }
+        }
+
+        private void imageSource_DragEnter(object sender, DragEventArgs e)
+        {
+            if (e.Data.GetDataPresent(DataFormats.FileDrop)) e.Effects = DragDropEffects.Copy;
+        }
+    }
+}
diff --git a/ENI2/MainWindow.xaml b/ENI2/MainWindow.xaml
index a33af61f..37d9d068 100644
--- a/ENI2/MainWindow.xaml
+++ b/ENI2/MainWindow.xaml
@@ -72,6 +72,7 @@
                         <ColumnDefinition Width="auto"/>
                         <ColumnDefinition Width="auto"/>
                         <ColumnDefinition Width="auto"/>
+                        <ColumnDefinition Width="auto"/>
                         <ColumnDefinition Width="*"/>
                     </Grid.ColumnDefinitions>
                     <Grid.RowDefinitions>
@@ -84,7 +85,8 @@
                     <RadioButton Grid.Column="3" x:Name="buttonStatus" Content="{x:Static p:Resources.textServerStatus}" HorizontalAlignment="Left" VerticalAlignment="Top" Width="auto" Click="radioButton_Click" Background="Transparent" Margin="2,5,0,0" Grid.RowSpan="2" />
                     <RadioButton Grid.Column="4" x:Name="buttonUserAdmin" Content="{x:Static p:Resources.textUserAdministration}" HorizontalAlignment="Left" VerticalAlignment="Top" Width="auto" Click="radioButton_Click" Background="Transparent" Visibility="Hidden" Margin="2,5,0,0" Grid.RowSpan="2"/>
                     <RadioButton Grid.Column="5" x:Name="buttonPOListe" Content="{x:Static p:Resources.textPOLists}" HorizontalAlignment="Left" VerticalAlignment="Top" Width="auto" Click="radioButton_Click" Background="Transparent" Visibility="Hidden" Margin="2,5,0,0" Grid.RowSpan="2" />
-                    <Button Grid.Column="5" x:Name="buttonAbout" Content="?" HorizontalAlignment="Right" VerticalAlignment="Top" Background="Transparent" Margin="0,2,2,0" Padding="5,0,5,0" Click="buttonAbout_Click" Grid.RowSpan="2"/>
+                    <Button Grid.Column="6" x:Name="buttonCompareSheets" Content="{x:Static p:Resources.textCompareExcel}" HorizontalAlignment="Left" VerticalAlignment="Top" Click="buttonCompareSheets_Click" Background="Transparent" Margin="2,2,0,0" />
+                    <Button Grid.Column="7" x:Name="buttonAbout" Content="?" HorizontalAlignment="Right" VerticalAlignment="Top" Background="Transparent" Margin="0,2,2,0" Padding="5,0,5,0" Click="buttonAbout_Click" Grid.RowSpan="2"/>
                     <Label Grid.Column="0" Grid.Row="1" x:Name="labelStatusId" Grid.ColumnSpan="3" Margin="2,2,0,0" HorizontalAlignment="Left"/>
                 </Grid>
             </Grid>
diff --git a/ENI2/MainWindow.xaml.cs b/ENI2/MainWindow.xaml.cs
index ae7de548..483bc33a 100644
--- a/ENI2/MainWindow.xaml.cs
+++ b/ENI2/MainWindow.xaml.cs
@@ -38,7 +38,8 @@ namespace ENI2
         private POListControl poControl;
         private ServerStatusControl statusControl;
         private readonly SucheControl sucheControl;
-        
+        private CompareExcelDialog compareExcelDialog;
+
         private bool efMode = false;
         private bool dbConnected;
         private readonly ScaleTransform _transform = new ScaleTransform(1.0, 1.0);
@@ -287,6 +288,22 @@ namespace ENI2
             this.buttonNewWithId.Visibility = newButtonsVisible ? Visibility.Visible : Visibility.Hidden;
         }
 
+        private void buttonCompareSheets_Click(object sender, RoutedEventArgs ev)
+        {
+            // Open compare dialog
+            if(compareExcelDialog == null)
+            {
+                this.compareExcelDialog = new CompareExcelDialog();
+                this.compareExcelDialog.Closed += (o, e) => this.compareExcelDialog = null;                
+                compareExcelDialog.Show();
+            }
+            else
+            {
+                compareExcelDialog.BringUp();
+            }
+
+        }
+
         #endregion
 
         #region window lifetime event handler
@@ -691,6 +708,6 @@ namespace ENI2
         }
 
         #endregion
-
+        
     }
 }
diff --git a/ENI2/Properties/Resources.Designer.cs b/ENI2/Properties/Resources.Designer.cs
index d7b6c951..6c73ca2f 100644
--- a/ENI2/Properties/Resources.Designer.cs
+++ b/ENI2/Properties/Resources.Designer.cs
@@ -1345,6 +1345,15 @@ namespace ENI2.Properties {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Compare excel sheets.
+        /// </summary>
+        public static string textCompareExcel {
+            get {
+                return ResourceManager.GetString("textCompareExcel", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Condition.
         /// </summary>
diff --git a/ENI2/Properties/Resources.resx b/ENI2/Properties/Resources.resx
index 214be32e..692a6d10 100644
--- a/ENI2/Properties/Resources.resx
+++ b/ENI2/Properties/Resources.resx
@@ -1840,4 +1840,7 @@
   <data name="textCopyTo" xml:space="preserve">
     <value>Copy to {0}</value>
   </data>
+  <data name="textCompareExcel" xml:space="preserve">
+    <value>Compare excel sheets</value>
+  </data>
 </root>
\ No newline at end of file