changed choosen to checkbox

calender/calender.py

         title = request.form['title']
         nickname = request.form['nickname']
         body = request.form['body']
-        chosen = request.form['chosen']
+        if request.form.get('chosen') is None:
+            chosen = 0
+        else:
+            chosen = 1
         error = None
 
         if not title:

calender/templates/calender/update.html

                    value="{{ request.form['file'] or post['file'] }}">
         </div>
         <label for="chosen">Chosen</label><br>
-        <input id="chosen" name="chosen" value="{{ request.form['chosen'] or post['chosen'] }}">
+        {% if post['chosen'] == 1 %}
+            <input id="chosen" type="checkbox" name="chosen" value="{{ request.form['chosen'] or post['chosen'] }}"
+                   checked/>
+        {% endif %}
+        {% if post['chosen'] == 0 %}
+            <input id="chosen" type="checkbox" name="chosen" value="{{ request.form['chosen'] or post['chosen'] }}"/>
+        {% endif %}
         <input type="submit" value="Save">
     </form>
     <hr>