Use EventBox as base class for ClickImage.

diff --git a/desktop.py b/desktop.py
index d0f3ad2..de3f7b9 100755
--- a/desktop.py
+++ b/desktop.py
@@ -33,9 +33,9 @@ def browse(title,filtername="",mimetypes=[],patterns=[]):
     chooser.destroy()
     return result

-class ClickImage(gtk.Button):
+class ClickImage(gtk.EventBox):
     def __init__(self):
-        gtk.Button.__init__(self)
+        gtk.EventBox.__init__(self)
         self.img = gtk.Image()
         self.img.show()
         self.add(self.img)