text: import os
  from flask import Flask, url_for, render_template, request
  from flask import redirect
  from flask import session
  
  app = Flask(__name__)
  
  # In order to use "sessions",you need a "secret key".
  # This is something random you generate.  
  # See: http://flask.pocoo.org/docs/0.10/quickstart/#sessions
  
  app.secret_key=os.environ["SECRET_KEY"]; #SECRET_KEY is an environment variable.  
                                           #The value should be set in Heroku (Settings->Config Vars).  
  
  @app.route('/')
  def renderMain():
     
      return render_template('home.html')
  
  @app.route('/startOver')
  def startOver():
      #TODO: delete everything from the session
      session.clear() #clears variables values and creates a new session
      return redirect('/')
  
  @app.route('/page1')
  def renderPage1():
      return render_template('page1.html')
  
  @app.route('/page2',methods=['GET','POST'])
  def renderPage2():
      #TODO: save the first and last name in the session
      session["firstName"]=request.form['firstName]
      return render_template('page2.html')
  
  @app.route('/page3',methods=['GET','POST'])
  def renderPage3():
      #TODO: save the favorite color in the session
      session["favoriteColor"]=request.form['favoriteColor']
      return render_template('page3.html')
      
  if __name__=="__main__":
      app.run(debug=False)
  