diff --git a/.gitattributes b/.gitattributes
index 2d38245d606..f2d7f25b762 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -206,7 +206,9 @@ Arrangement_2/demo/Arrangement_2/icons/demo_split.bmp -text svneol=unset#image/b
 Arrangement_2/demo/Arrangement_2/icons/demo_zoomin.bmp -text svneol=unset#image/bmp
 Arrangement_2/demo/Arrangement_2/icons/demo_zoomout.bmp -text svneol=unset#image/bmp
 Arrangement_2/demo/Arrangement_2/icons/lower_env_xpm.bmp -text
+Arrangement_2/demo/Arrangement_2/icons/lower_env_xpm.xpm -text
 Arrangement_2/demo/Arrangement_2/icons/upper_env_xpm.bmp -text
+Arrangement_2/demo/Arrangement_2/icons/upper_env_xpm.xpm -text
 Arrangement_2/doc_tex/Arrangement_2/fig/Bezier_arr.eps -text svneol=unset#application/postscript
 Arrangement_2/doc_tex/Arrangement_2/fig/Bezier_arr.gif -text svneol=unset#image/gif
 Arrangement_2/doc_tex/Arrangement_2/fig/Bezier_arr.pdf -text svneol=unset#application/pdf
diff --git a/Arrangement_2/demo/Arrangement_2/MyWindow.cpp b/Arrangement_2/demo/Arrangement_2/MyWindow.cpp
index 43cdd56985c..c88ba404974 100644
--- a/Arrangement_2/demo/Arrangement_2/MyWindow.cpp
+++ b/Arrangement_2/demo/Arrangement_2/MyWindow.cpp
@@ -56,8 +56,8 @@
 #include "icons/demo_conic_segment.xpm"
 #include "icons/demo_rayshoot_down.xpm"
 #include "icons/demo_rayshoot_up.xpm"
-//#include "icons/demo_arrow_down.xpm"
-//#include "icons/demo_arrow_up.xpm"
+#include "icons/lower_env_xpm.xpm"
+#include "icons/upper_env_xpm.xpm"
 #include "icons/demo_fill.xpm"
 #include "icons/demo_colors.xpm"
 
@@ -178,11 +178,11 @@ MyWindow::MyWindow(int w, int h) : num_of_colors(18)
   color_dialog_bt = new QAction("Choose color", QPixmap( (const char**)demo_colors_xpm ),
                          "&choose color", 0 , this, "choose color" );
 
-  lower_env_dialog_bt = new QAction("Lower envelope", QPixmap( (const char**)demo_colors_xpm ),
+  lower_env_dialog_bt = new QAction("Lower envelope", QPixmap( (const char**)lower_env_xpm ),
                              "&lower envelope", 0, this, "Lower envelop" );
   lower_env_dialog_bt->setToggleAction( TRUE );
 
-  upper_env_dialog_bt = new QAction("Upper envelope", QPixmap( (const char**)demo_colors_xpm ),
+  upper_env_dialog_bt = new QAction("Upper envelope", QPixmap( (const char**)upper_env_xpm ),
                              "&upper envelope", 0, this, "Upper envelop" );
   upper_env_dialog_bt->setToggleAction( TRUE );
   
@@ -448,7 +448,7 @@ int main(int argc, char **argv)
 {
   const QString my_title_string("Arrangement Demo with CGAL Qt_widget");
   QApplication app( argc, argv );
-  MyWindow widget(700,700); // physical window size
+  MyWindow widget(707,707); // physical window size
   app.setMainWidget(&widget);
   widget.setCaption(my_title_string);
   widget.setMouseTracking(TRUE);
diff --git a/Arrangement_2/demo/Arrangement_2/icons/lower_env_xpm.xpm b/Arrangement_2/demo/Arrangement_2/icons/lower_env_xpm.xpm
new file mode 100644
index 00000000000..56e464d1fa0
--- /dev/null
+++ b/Arrangement_2/demo/Arrangement_2/icons/lower_env_xpm.xpm
@@ -0,0 +1,44 @@
+/* XPM */
+static char *lower_env_xpm[] = {
+/* width height ncolors chars_per_pixel */
+"32 32 5 1",
+/* colors */
+"  c #000000",
+". c #00FFFF",
+"X c #FF0000",
+"o c None",
+"O c None",
+/* pixels */
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oo                           ooo",
+"oo   .....................   ooo",
+"oo .  ...................  . ooo",
+"oo ..   ................  .. ooo",
+"oo ....  .............  .... ooo",
+"oo .....  ...........  ..... ooo",
+"oo ......  .........  ...... ooo",
+"oo .......  .......  ....... ooo",
+"oo ......     ...     ...... ooo",
+"oo .....  ..      ...  ..... ooo",
+"oo ....  .....  ......  .... ooo",
+"oo ...  ...............  ... ooo",
+"oo ..  .................  .. ooo",
+"oo .  ...................  . ooo",
+"oo   .....................   ooo",
+"oo                           ooo",
+"ooXXXXXXXXXXXXXXXXXXXXXXXXXXXooo",
+"oooXXXXXXXXXXXXXXXXXXXXXXXXXoooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo"
+};
diff --git a/Arrangement_2/demo/Arrangement_2/icons/upper_env_xpm.xpm b/Arrangement_2/demo/Arrangement_2/icons/upper_env_xpm.xpm
new file mode 100644
index 00000000000..c694ea72b11
--- /dev/null
+++ b/Arrangement_2/demo/Arrangement_2/icons/upper_env_xpm.xpm
@@ -0,0 +1,44 @@
+/* XPM */
+static char *upper_env_xpm[] = {
+/* width height ncolors chars_per_pixel */
+"32 32 5 1",
+/* colors */
+"  c #000000",
+". c #00FFFF",
+"X c #FF0000",
+"o c None",
+"O c None",
+/* pixels */
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooXXXXXXXXXXXXXXXXXXXXXXXXXoooo",
+"ooXXXXXXXXXXXXXXXXXXXXXXXXXXXooo",
+"oo                           ooo",
+"oo   .....................   ooo",
+"oo .  ...................  . ooo",
+"oo ..   ................  .. ooo",
+"oo ....  .............  .... ooo",
+"oo .....  ...........  ..... ooo",
+"oo ......  .........  ...... ooo",
+"oo .......  .......  ....... ooo",
+"oo ......     ...     ...... ooo",
+"oo .....  ..      ...  ..... ooo",
+"oo ....  .....  ......  .... ooo",
+"oo ...  ...............  ... ooo",
+"oo ..  .................  .. ooo",
+"oo .  ...................  . ooo",
+"oo   .....................   ooo",
+"oo                           ooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo",
+"oooooooooooooooooooooooooooooooo"
+};