diff --git a/tools/cooja/java/se/sics/cooja/contikimote/ContikiMoteTypeDialog.java b/tools/cooja/java/se/sics/cooja/contikimote/ContikiMoteTypeDialog.java
index e04be2b8f..b170be817 100644
--- a/tools/cooja/java/se/sics/cooja/contikimote/ContikiMoteTypeDialog.java
+++ b/tools/cooja/java/se/sics/cooja/contikimote/ContikiMoteTypeDialog.java
@@ -26,7 +26,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: ContikiMoteTypeDialog.java,v 1.15 2007/01/10 08:48:13 fros4943 Exp $
+ * $Id: ContikiMoteTypeDialog.java,v 1.16 2007/03/22 09:34:50 fros4943 Exp $
  */
 
 package se.sics.cooja.contikimote;
@@ -126,7 +126,8 @@ public class ContikiMoteTypeDialog extends JDialog {
 
     final ContikiMoteTypeDialog myDialog = new ContikiMoteTypeDialog(
         parentFrame);
-
+    myDialog.setDefaultCloseOperation(JDialog.DO_NOTHING_ON_CLOSE);
+    
     myDialog.myMoteType = moteTypeToConfigure;
     myDialog.myGUI = simulation.getGUI();
     myDialog.allOtherTypes = simulation.getMoteTypes();
@@ -807,6 +808,31 @@ public class ContikiMoteTypeDialog extends JDialog {
     contentPane.add(mainScrollPane, BorderLayout.CENTER);
     contentPane.add(buttonPane, BorderLayout.SOUTH);
 
+    addWindowListener(new WindowListener() {
+      public void windowDeactivated(WindowEvent e) {
+      }
+
+      public void windowIconified(WindowEvent e) {
+      }
+
+      public void windowDeiconified(WindowEvent e) {
+      }
+
+      public void windowOpened(WindowEvent e) {
+      }
+
+      public void windowClosed(WindowEvent e) {
+      }
+
+      public void windowActivated(WindowEvent e) {
+      }
+
+      public void windowClosing(WindowEvent e) {
+        myMoteType = null;
+        dispose();
+      }
+    });
+
     // pack();
   }