diff --git a/AboutBox.Designer.cs b/AboutBox.Designer.cs
index 82dd05a..c8f7313 100644
--- a/AboutBox.Designer.cs
+++ b/AboutBox.Designer.cs
@@ -29,13 +29,13 @@ private void InitializeComponent()
         {
             System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(AboutBox));
             this.tableLayoutPanel = new System.Windows.Forms.TableLayoutPanel();
+            this.logoPictureBox = new System.Windows.Forms.PictureBox();
             this.labelProductName = new System.Windows.Forms.Label();
             this.labelVersion = new System.Windows.Forms.Label();
             this.labelCopyright = new System.Windows.Forms.Label();
             this.labelCompanyName = new System.Windows.Forms.Label();
             this.textBoxDescription = new System.Windows.Forms.TextBox();
             this.okButton = new System.Windows.Forms.Button();
-            this.logoPictureBox = new System.Windows.Forms.PictureBox();
             this.tableLayoutPanel.SuspendLayout();
             ((System.ComponentModel.ISupportInitialize)(this.logoPictureBox)).BeginInit();
             this.SuspendLayout();
@@ -65,6 +65,17 @@ private void InitializeComponent()
             this.tableLayoutPanel.Size = new System.Drawing.Size(432, 254);
             this.tableLayoutPanel.TabIndex = 0;
             // 
+            // logoPictureBox
+            // 
+            this.logoPictureBox.Dock = System.Windows.Forms.DockStyle.Fill;
+            this.logoPictureBox.Image = global::DSA_lims.Properties.Resources.dsa_logo_1461;
+            this.logoPictureBox.Location = new System.Drawing.Point(3, 3);
+            this.logoPictureBox.Name = "logoPictureBox";
+            this.tableLayoutPanel.SetRowSpan(this.logoPictureBox, 6);
+            this.logoPictureBox.Size = new System.Drawing.Size(141, 248);
+            this.logoPictureBox.TabIndex = 12;
+            this.logoPictureBox.TabStop = false;
+            // 
             // labelProductName
             // 
             this.labelProductName.Dock = System.Windows.Forms.DockStyle.Fill;
@@ -136,17 +147,7 @@ private void InitializeComponent()
             this.okButton.Size = new System.Drawing.Size(75, 21);
             this.okButton.TabIndex = 24;
             this.okButton.Text = "&OK";
-            // 
-            // logoPictureBox
-            // 
-            this.logoPictureBox.Dock = System.Windows.Forms.DockStyle.Fill;
-            this.logoPictureBox.Image = global::DSA_lims.Properties.Resources.dsa_logo_1461;
-            this.logoPictureBox.Location = new System.Drawing.Point(3, 3);
-            this.logoPictureBox.Name = "logoPictureBox";
-            this.tableLayoutPanel.SetRowSpan(this.logoPictureBox, 6);
-            this.logoPictureBox.Size = new System.Drawing.Size(141, 248);
-            this.logoPictureBox.TabIndex = 12;
-            this.logoPictureBox.TabStop = false;
+            this.okButton.Click += new System.EventHandler(this.okButton_Click);
             // 
             // AboutBox
             // 
diff --git a/AboutBox.cs b/AboutBox.cs
index e486f91..2f44815 100644
--- a/AboutBox.cs
+++ b/AboutBox.cs
@@ -101,5 +101,10 @@ public string AssemblyCompany
             }
         }
         #endregion
+
+        private void okButton_Click(object sender, EventArgs e)
+        {
+
+        }
     }
 }
diff --git a/DSA-LIMS_MANUAL.pdf b/DSA-LIMS_MANUAL.pdf
index 1b03b8e..82c7d9f 100644
Binary files a/DSA-LIMS_MANUAL.pdf and b/DSA-LIMS_MANUAL.pdf differ
diff --git a/FormLogin.cs b/FormLogin.cs
index 4fd5d82..09758a9 100644
--- a/FormLogin.cs
+++ b/FormLogin.cs
@@ -25,6 +25,7 @@ You should have received a copy of the GNU General Public License
 using System.DirectoryServices.ActiveDirectory;
 using System.Drawing;
 using System.Linq;
+using System.Reflection;
 using System.Security.Principal;
 using System.Text;
 using System.Windows.Forms;
@@ -71,6 +72,16 @@ private void btnOk_Click(object sender, EventArgs e)
 
                 trans = conn.BeginTransaction();
 
+                int client_version, database_version;
+
+                GetVersionInfo(conn, trans, out client_version, out database_version);
+
+                if (client_version != database_version)
+                {
+                    MessageBox.Show("Incompatible database. Client expects version " + client_version + " but database has version " + database_version);
+                    return;
+                }
+
                 if (cboxAction.SelectedIndex == 0)
                 {
                     string username = tbUsername.Text.ToLower().Trim();
@@ -130,6 +141,14 @@ private void btnOk_Click(object sender, EventArgs e)
             }
         }
 
+        private void GetVersionInfo(SqlConnection conn, SqlTransaction trans, out int client_version, out int database_version)
+        {
+            client_version = Assembly.GetExecutingAssembly().GetName().Version.Major;
+
+            SqlCommand cmd = new SqlCommand("select value from counters where name = 'database_version'", conn, trans);
+            database_version = (int)cmd.ExecuteScalar();
+        }
+
         private bool CreateLIMSAdministrator(SqlConnection conn, SqlTransaction trans)
         {
             FormCreateLIMSAdministrator form = new FormCreateLIMSAdministrator();
diff --git a/FormMain.Designer.cs b/FormMain.Designer.cs
index 3a3bb32..357728d 100644
--- a/FormMain.Designer.cs
+++ b/FormMain.Designer.cs
@@ -4471,7 +4471,7 @@ private void InitializeComponent()
             // btnOrderDelSampleType
             // 
             this.btnOrderDelSampleType.Name = "btnOrderDelSampleType";
-            this.btnOrderDelSampleType.Size = new System.Drawing.Size(152, 22);
+            this.btnOrderDelSampleType.Size = new System.Drawing.Size(139, 22);
             this.btnOrderDelSampleType.Text = "Sample type";
             this.btnOrderDelSampleType.Click += new System.EventHandler(this.miOrderRemSampleType_Click);
             // 
diff --git a/Properties/AssemblyInfo.cs b/Properties/AssemblyInfo.cs
index 420d553..d57c802 100644
--- a/Properties/AssemblyInfo.cs
+++ b/Properties/AssemblyInfo.cs
@@ -32,5 +32,5 @@
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
 // [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("0.0.*")]
+[assembly: AssemblyVersion("1.1.*")]
 [assembly: AssemblyFileVersion("0.0.0.0")]
diff --git a/database.sql b/database.sql
index 4e0bb9f..56da312 100644
--- a/database.sql
+++ b/database.sql
@@ -157,6 +157,7 @@ create table counters (
 )
 go
 
+insert into counters (name) values('database_version')
 insert into counters (name) values('sample_counter')
 go