diff --git a/.gitignore b/.gitignore
index e4b0aa2..f5bfdaa 100755
--- a/.gitignore
+++ b/.gitignore
@@ -129,3 +129,12 @@ dmypy.json
 .pyre/
 
 config.ini
+videos/
+*.mp4
+*.webm
+*.mkv
+*.avi
+*.ogv
+*.ogg
+*.mp3
+*.flac
\ No newline at end of file
diff --git a/mail.py b/mail.py
index 5f4ec2d..ad2f7e6 100755
--- a/mail.py
+++ b/mail.py
@@ -1,4 +1,8 @@
-import configparser, email, os, smtplib, ssl
+import configparser
+import email
+import os
+import smtplib
+import ssl
 
 from email import encoders
 from email.mime.base import MIMEBase
@@ -8,39 +12,40 @@ from email.mime.text import MIMEText
 config = configparser.ConfigParser()
 config.read('config.ini')
 
+
 def send_email(destination, attachment):
     subject = 'Your modified video'
     body = 'You have recently used our service to modify a video. The result is attached.'
     sender_email = config.get('Mail', 'Username')
     receiver_email = destination
     password = config.get('Mail', 'Password')
-    
+
     # Create a multipart message and set headers
     message = MIMEMultipart()
     message['From'] = sender_email
     message['To'] = receiver_email
     message['Subject'] = subject
-    
+
     # Add body to email
     message.attach(MIMEText(body, 'plain'))
 
     with open(attachment, 'rb') as file:
         part = MIMEBase('application', 'octet-stream')
         part.set_payload(file.read())
-    
+
     # Encode file in ASCII characters to send by email
     encoders.encode_base64(part)
-    
+
     # Add header as key/value pair to attachment part
     part.add_header(
         'Content-Disposition',
         f'attachment; filename= {os.path.normpath(attachment)}',
     )
-    
+
     # Add attachment to message and convert message to string
     message.attach(part)
     text = message.as_string()
-    
+
     # Log in to server using secure context and send email
     if config.getboolean('Mail', 'SSL'):
         context = ssl.create_default_context()
diff --git a/main.py b/main.py
index a1fcda6..988300b 100755
--- a/main.py
+++ b/main.py
@@ -10,12 +10,15 @@ import moviepy.editor as moviepy
 app = Flask(__name__)
 
 ALLOWED_UPLOAD_EXTENSIONS = {'mp4', 'webm', 'mkv', 'avi', 'ogv'}
-ALLOWED_CONVERT_EXTENSIONS = {'mp4', 'webm', 'mkv', 'avi', 'ogv', 'ogg', 'mp3', 'flac'}
+ALLOWED_CONVERT_EXTENSIONS = {'mp4', 'webm',
+                              'mkv', 'avi', 'ogv', 'ogg', 'mp3', 'flac'}
 AUDIO_EXTENSIONS = {'ogg', 'mp3', 'flac'}
-ALLOWED_WATERMARK_EXTENSIONS = {'bmp', 'png', 'jpg', 'jpeg', 'tiff', 'tga', 'svg'}
+ALLOWED_WATERMARK_EXTENSIONS = {
+    'bmp', 'png', 'jpg', 'jpeg', 'tiff', 'tga', 'svg'}
 
 percentages = {}
 
+
 class BarLogger(ProgressBarLogger):
     global percentages
     id = None
@@ -27,12 +30,14 @@ class BarLogger(ProgressBarLogger):
         super(self.__class__, self).__init__()
         self.id = id
 
+
 def is_integer(n):
     try:
         return float(n).is_integer()
     except ValueError:
         return False
 
+
 def getExtension(filename, isWatermark=False):
     if not '.' in filename:
         return False
@@ -44,6 +49,7 @@ def getExtension(filename, isWatermark=False):
     else:
         return False
 
+
 @app.route('/', methods=['GET', 'POST'])
 def index():
     if request.method == 'POST' and 'video' in request.files:
@@ -59,12 +65,15 @@ def index():
 
     return render_template('index.html')
 
+
 @app.route('/video', methods=['GET', 'POST'])
 def video():
     error = ''
     changed = False
     audio = None
     id = request.args.get('id')
+    if id == None:
+        abort(400)
     path = os.path.join('videos', id)
     if id != None and os.path.isfile(path):
         clip = moviepy.VideoFileClip(path)
@@ -101,20 +110,23 @@ def video():
                     else:
                         watermarkExtension = getExtension(file.filename, True)
                         if watermarkExtension:
-                            watermarkPath = os.path.join('videos', id + '-watermark' + '.' + watermarkExtension)
+                            watermarkPath = os.path.join(
+                                'videos', id + '-watermark' + '.' + watermarkExtension)
                             file.save(watermarkPath)
 
                             formatter = {'PNG': 'RGBA', 'JPEG': 'RGB'}
                             img = Image.open(watermarkPath)
-                            rgbimg = Image.new(formatter.get(img.format, 'RGB'), img.size)
+                            rgbimg = Image.new(formatter.get(
+                                img.format, 'RGB'), img.size)
                             rgbimg.paste(img)
                             rgbimg.save(watermarkPath, format=img.format)
 
                             watermark = (moviepy.ImageClip(watermarkPath)
-                                .set_duration(clip.duration)
-                                .set_pos(('right', 'bottom')))
+                                         .set_duration(clip.duration)
+                                         .set_pos(('right', 'bottom')))
 
-                            clip = moviepy.CompositeVideoClip([clip, watermark])
+                            clip = moviepy.CompositeVideoClip(
+                                [clip, watermark])
                             os.remove(watermarkPath)
                             changed = True
                         else:
@@ -133,10 +145,11 @@ def video():
                 os.remove(path)
                 return render_template('success.html', error=error)
 
-        return render_template('video.html', id=id, length=int(clip.duration), error=error)
+        return render_template('video.html', length=int(clip.duration), error=error)
     else:
         abort(404)
 
+
 @app.route('/progress', methods=['GET'])
 def progress():
     id = request.args.get('id')
@@ -146,6 +159,7 @@ def progress():
     else:
         abort(404)
 
+
 if __name__ == '__main__':
     if not os.path.isdir('videos'):
         os.mkdir('videos')
diff --git a/templates/index.html b/templates/index.html
index 555ccb8..a88c864 100755
--- a/templates/index.html
+++ b/templates/index.html
@@ -1,8 +1,10 @@
 <!DOCTYPE html>
 <html lang="en">
+
 <head>
     <title>Video upload</title>
 </head>
+
 <body>
     {% if error %}
     <p>{{ error | safe }}</p>
@@ -13,5 +15,5 @@
         <button id="submit" type="submit">Submit</button>
     </form>
 </body>
-    </p>
-</html>
+
+</html>
\ No newline at end of file
diff --git a/templates/success.html b/templates/success.html
index 9d2346f..a41c7f6 100755
--- a/templates/success.html
+++ b/templates/success.html
@@ -1,15 +1,17 @@
 <!DOCTYPE html>
 <html lang="en">
+
 <head>
     <title>Video upload</title>
 </head>
+
 <body>
     <p>The modified video was sent to your email address. You can upload another one if you want to.</p>
     {% if error %}
     <p>The following errors occurred:<br>
-    {{ error | safe }}</p>
+        {{ error | safe }}</p>
     {% endif %}
     <p><a href="index.html">Upload another video</a></p>
 </body>
-    </p>
-</html>
+
+</html>
\ No newline at end of file
diff --git a/templates/video.html b/templates/video.html
index 4fda2c6..6acef45 100755
--- a/templates/video.html
+++ b/templates/video.html
@@ -1,13 +1,15 @@
 <!DOCTYPE html>
 <html lang="en">
+
 <head>
     <title>Video editing</title>
 </head>
+
 <body>
     {% if error %}
     <p>{{ error | safe }}</p>
     {% endif %}
-    <p>Video {{name}} ({{length}})</p>
+    <p>Video length: {{length}} s</p>
     <form method="POST" enctype="multipart/form-data" onsubmit="trackProgress()">
         <label for="start">Start (s): </label><br>
         <input type="text" id="start" name="start"><br>
@@ -27,7 +29,7 @@
             const urlParams = new URLSearchParams(window.location.search);
             const id = urlParams.get('id');
             const xhttp = new XMLHttpRequest();
-            xhttp.onload = function() {
+            xhttp.onload = function () {
                 document.getElementById("bar").value = this.responseText;
             }
             xhttp.open("GET", "/progress?id=" + id, true);
@@ -42,4 +44,5 @@
     </script>
 
 </body>
-</html>
+
+</html>
\ No newline at end of file