title: Flask-WTF form doesn't have attribute 'validate_on_submit'
body: <p>I am using Flask-WTF to validate a form when submitted.  I am using <code>form.validate_on_submit()</code>, but I get the following error:</p>
  
  <pre><code>AttributeError: 'PickASong' object has no attribute 'validate_on_submit'
  </code></pre>
  
  <p>Why am I getting this error, and how do I fix it?</p>
  
  <pre><code>import flask
  from flask import Flask
  from flask import render_template
  from flask import Flask
  from flask import request
  from flask import render_template
  from flask import redirect
  from flask.ext.wtf import Form
  from wtforms import *
  from wtforms import StringField, BooleanField
  from wtforms.validators import DataRequired
  from flask.ext.wtf import Form
  from wtforms import Form, TextField, BooleanField, PasswordField, TextAreaField, validators
  
  class PickASong(Form):
      song = TextField(u'Song title', validators=[DataRequired()])
  
  class PickAnumber(Form):
      songNumber = IntegerField(u'Please select song number', validators=[DataRequired()])
  
  app = Flask(__name__)
  
  @app.route("/",methods=["POST","GET"])
  def hello():
      form = PickASong(csrf_enabled=False)
  
      if form.validate_on_submit():
          user = form.song.data
          print user
          d=str(user)
          print d
          # search(d)
          cmd = "python Search.py --q \"" + d +'"'
          os.system(cmd)
          return redirect('/2')
  
      return render_template('searchtwo.html', form=form)
  </code></pre>