direct sharing of files

code/templates/send.html

@@ -3,7 +3,7 @@
   upload to {{ name|safe  }}
   <form action={{ url_for('upload') }} method=post enctype=multipart/form-data>
     <input type=hidden name=name value="{{ name|safe }}" />
-     <p><input type=file name=file>
-       <input type=submit value=Upload>
+     <p><input type=file name=file onchange="function() { document.getElementById('upload_button').disabled = false; }">
+         <input id="upload_button" type=submit value=Upload disabled>   
   </form>
 {% endblock %}