br.set_handle_equiv(True)
br.set_handle_redirect(True)
br.set_handle_robots(False)
email = 'your@email.com'
password = 'your_pass'
br = mechanize.Browser()
br.open('https://vk.com/')
br.select_form(nr=0)
br.form['email'] = email
br.form['pass'] = password
br.submit()
br.open('destination_url')
response = br.response().read()