title: Add row to Form Layout
body: <p>code:</p>
  
  <pre><code>import sys
  from PySide.QtCore import *
  from PySide.QtGui import *
  
  def main():
      app = QApplication(sys.argv)
      main = QMainWindow()
      main.setWindowTitle("First GUI")
      form_widget = QWidget()
      form_widget.layout = QFormLayout()
      form_widget.layout.addRow(QLabel("city 1"), QLabel("delhi"))
      form_widget.layout.addRow(QLabel("city 2"), QLabel("chennai"))
      main.setCentralWidget(form_widget)
  
      main.show()
      sys.exit(app.exec_())
  
  if __name__ == '__main__':
      main()
  </code></pre>
  
  <p>Above code opened an empty window with "First GUI" as title.</p>
  
  <p>But rows were not added to that window. <em>Why ? How to correct this ?</em></p>