diff --git a/README.md b/README.md
old mode 100644
new mode 100755
index 54441be..eb8983f
--- a/README.md
+++ b/README.md
@@ -20,9 +20,9 @@ This tool can run on Linux, Windows and MAC.
 
 ## Install and Run
 
-1. pip install Flask-Bootstrap pyscreenshot
+1. pip install flask-bootstrap pyscreenshot
 
-2. In a directory, run "**git clone https://gitlab.com/qijungu/screenshare.git**". You will have a new directory "screenshare" with code inside.
+2. In a directory, run "**git clone https://github.com/qijungu/screenshare.git**". You will have a new directory "screenshare" with code inside.
 
 3. To start the screen sharing service, run "**python screenshare.py [port]**".
 
diff --git a/__init__.py b/__init__.py
old mode 100644
new mode 100755
diff --git a/screen.py b/screen.py
old mode 100644
new mode 100755
index d630858..f8c336d
--- a/screen.py
+++ b/screen.py
@@ -1,13 +1,24 @@
 # -*- coding: utf-8 -*-
 
-import threading, StringIO, time, base64
+import threading, time, base64
 import pyscreenshot as ig
 
+import sys
+
+ver = sys.version_info.major
+if ver==2:
+    import StringIO
+elif ver==3:
+    import io
+
 class Screen():
     def __init__(self):
         self.FPS = 10
         self.screenbuf = ""
-        self.screenfile = StringIO.StringIO()
+        if ver==2:
+            self.screenfile = StringIO.StringIO()
+        elif ver==3:
+            self.screenfile = io.BytesIO()
         threading.Thread(target=self.getframes).start()
 
     def __del__(self):
@@ -15,13 +26,19 @@ class Screen():
 
     def getframes(self):
         while True:
-            im = ig.grab(childprocess=False)
+            im = ig.grab(childprocess=False,backend="pygdk3")
+            self.screenfile.seek(0)
             self.screenfile.truncate(0)
             im.save(self.screenfile, format="jpeg", quality=75, progressive=True)
             self.screenbuf = base64.b64encode(self.screenfile.getvalue())
             time.sleep(1.0/self.FPS)
     
     def gen(self):
-        return self.screenbuf
+        s = ''
+        if ver==2:
+            s = self.screenbuf
+        elif ver==3:
+            s = self.screenbuf.decode()
+        return s
     
-screenlive = Screen()
\ No newline at end of file
+screenlive = Screen()
diff --git a/screenshare.py b/screenshare.py
old mode 100644
new mode 100755
index 8d54823..964c71a
--- a/screenshare.py
+++ b/screenshare.py
@@ -1,3 +1,4 @@
+#!/usr/bin/python
 # -*- coding: utf-8 -*-
 
 from flask import Flask
diff --git a/static/css/common.css b/static/css/common.css
old mode 100644
new mode 100755
diff --git a/static/css/jquery-confirm.min.css b/static/css/jquery-confirm.min.css
old mode 100644
new mode 100755
diff --git a/static/js/jquery-confirm.min.js b/static/js/jquery-confirm.min.js
old mode 100644
new mode 100755
diff --git a/static/js/screen.js b/static/js/screen.js
old mode 100644
new mode 100755
diff --git a/templates/screen.html b/templates/screen.html
old mode 100644
new mode 100755