-import avahi, dbus, gobject, sys
-from avahi.SimpleGladeApp import SimpleGladeApp
+try:
+ import avahi, gtk, gobject, dbus
+ from avahi.SimpleGladeApp import SimpleGladeApp
+except ImportError:
+ print "Sorry, to use this tool you need to install Avahi, pygtk and python-dbus."
+ sys.exit(1)