diff --git a/vviewer/vviewer.py b/vviewer/vviewer.py
old mode 100644
new mode 100755
index 98aa60ed4c388ff57cf934d7042af435221661c8..01f172111e3277708feae559672741b9df7f0c9e
--- a/vviewer/vviewer.py
+++ b/vviewer/vviewer.py
@@ -34,6 +34,8 @@ setapi("QVariant", 2)
 setapi("QString", 2)
 setapi("QUrl", 2)
 
+verbose_level = 5
+
 
 from pyqtgraph.Qt import QtCore, QtGui
 import numpy as np
@@ -77,6 +79,7 @@ from JumpSlider import JumpSlider
 from testInputs import testFloat, testInteger
 # print infos if necessary
 from Verboseprint import verboseprint
+import time
 
 try:
     _fromUtf8 = QtCore.QString.fromUtf8
@@ -91,6 +94,15 @@ except AttributeError:
     def _translate(context, text, disambig):
         return QtGui.QApplication.translate(context, text, disambig)
 
+def log1(msg):
+    if verbose_level <= 1:
+        print("log1 {}: {}".format(get_time(),msg))
+
+def get_time():
+    current_time = time.localtime()
+    str_time = time.strftime('%H%M%S', current_time)
+    return str_time
+
 
 class vviewer(QtGui.QMainWindow):
     """
@@ -477,6 +489,7 @@ class vviewer(QtGui.QMainWindow):
         self.fb_button.setToolTip("move to start")
         self.l.addWidget(self.fb_button, 8, self.listoffset+2, 1, 1)
 
+        #%% forward/backward one frame button
         # forward one frame button
         self.forward_button = QtGui.QToolButton(self)
         self.forward_button.pressed.connect(self.nextFrame)
@@ -2455,18 +2468,25 @@ class vviewer(QtGui.QMainWindow):
         self.setFrameToBox()
         self.setFrameToSlider()
 
+    #%% nextFrame function
     def nextFrame(self):
         """
         Goes to the next frame.
         """
+        
         self.frame = self.frame+1
         if self.frame >= self.time_dim:
             self.frame = self.time_dim - 1
+            
         else:
             self.setSliceStateOn()
             self.setFrame()
             self.setFrameToBox()
             self.setFrameToSlider()
+            self.setSliceStateOff()
+            
+            
+            
 
     def prevFrame(self):
         """
@@ -2480,6 +2500,7 @@ class vviewer(QtGui.QMainWindow):
             self.setFrame()
             self.setFrameToBox()
             self.setFrameToSlider()
+            self.setSliceStateOff()
 
     def setPlayState(self, play):
         """
@@ -2581,6 +2602,7 @@ class vviewer(QtGui.QMainWindow):
         This includes resampling the images, updating the ImageItemMods, all
         labels, the histogram and frame line edit and frame slider.
         """
+        # print("setframe called!")
         # Index for histogram update.
         index = self.imagelist.currentRow()
         # Move the frame number within the possible range.
@@ -2609,7 +2631,9 @@ class vviewer(QtGui.QMainWindow):
         self.updateCrossIntensityLabel()
         self.setFrameToBox()
         self.setFrameToSlider()
+        log1("setFrame called (self.frame {})".format(self.frame))
 
+    #%% setFrameFromSlider  function
     def setFrameFromSlider(self):
         """
         Takes the slider frame value and resets the current frame.
@@ -2619,6 +2643,7 @@ class vviewer(QtGui.QMainWindow):
             self.setSliceStateOn()
             self.frame = self.frame_sld.value()
             self.setFrame()
+        log1("setFrameFromSlider called (self.frame {})".format(self.frame))
 
     def setFrameToSlider(self):
         """
@@ -2628,6 +2653,7 @@ class vviewer(QtGui.QMainWindow):
         self.frame_write_block = True
         self.frame_sld.setValue(self.frame)
         self.frame_write_block = False
+        log1("setFrameToSlider called (self.frame {})".format(self.frame))
 
     ## Section: Color Map Thresholds Settings ##
     def setThresholdsFromHistogram(self):
@@ -3392,3 +3418,4 @@ def start_viewer():
 
 if __name__ == '__main__':
     main()
+