diff --git a/postpic/datahandling.py b/postpic/datahandling.py
index fadb484a..d9fe8acf 100644
--- a/postpic/datahandling.py
+++ b/postpic/datahandling.py
@@ -93,7 +93,8 @@ def extent(self):
         if len(self._grid_node) < 2:
             ret = None
         else:
-            return [self._grid_node[0], self._grid_node[-1]]
+            ret = [self._grid_node[0], self._grid_node[-1]]
+        return ret
 
     @property
     def label(self):
@@ -366,10 +367,10 @@ def exporttocsv(self, filename):
         if self.dimensions == 1:
             data = np.asarray(self.matrix)
             x = np.linspace(self.extent[0], self.extent[1], len(data))
-            np.savetxt(dateiname, np.transpose([x, data]), delimiter=' ')
+            np.savetxt(filename, np.transpose([x, data]), delimiter=' ')
         elif self.dimensions == 2:
             export = np.asarray(self.matrix)
-            np.savetxt(dateiname, export)
+            np.savetxt(filename, export)
         else:
             raise Exception('Not Implemented')
         return
diff --git a/test/test_datahandling.py b/test/test_datahandling.py
index 9bb02f67..f4b76599 100644
--- a/test/test_datahandling.py
+++ b/test/test_datahandling.py
@@ -90,6 +90,18 @@ def checkFieldConsistancy(self, field):
         for i in xrange(len(field.axes)):
             self.assertEqual(len(field.axes[i]), field.matrix.shape[i])
 
+    def test_extent(self):
+        self.assertListEqual(list(self.f0d.extent), [])
+        self.assertListEqual(list(self.f1d.extent), [0, 1])
+        self.f1d.extent = [3.3, 5.5]
+        self.assertListEqual(list(self.f1d.extent), [3.3, 5.5])
+        self.assertListEqual(list(self.f2d.extent), [0, 1, 0, 1])
+        self.f2d.extent = [3.3, 5.5, 7.7, 9.9]
+        self.assertListEqual(list(self.f2d.extent), [3.3, 5.5, 7.7, 9.9])
+        self.assertListEqual(list(self.f3d.extent), [0, 1, 0, 1, 0, 1])
+        self.f3d.extent = [3.3, 5.5, 7.7, 9.9, 11.1, 13.3]
+        self.assertListEqual(list(self.f3d.extent), [3.3, 5.5, 7.7, 9.9, 11.1,13.3])
+
     def test_dimensions(self):
         self.assertEqual(self.fempty.dimensions, -1)
         self.assertEqual(self.f0d.dimensions, 0)