title: PyQT Open another window from a button
body: <p>I am trying to open another window:</p>
  
  <pre><code>import FrmGuardar
  forma = FrmGuardar 
  QtCore.QObject.connect(self.actionPrimer_Formulario, QtCore.SIGNAL(_fromUtf8("triggered()")), OpenWindow)
  </code></pre>
  
  <p>The function I am using is:</p>
  
  <pre><code>def OpenWindow():
      import sys
      app = QtGui.QApplication(sys.argv)
      FrmGuardar = QtGui.QWidget()
      ui = forma.Ui_FrmGuardar()
      ui.setupUi(FrmGuardar)
      FrmGuardar.show()
      sys.exit(app.exec_())
  </code></pre>
  
  <p>The window appears, but then disappears instantly. I require assistance in solving this issue.</p>