title: Python3 PyQt4 Creating a simple QCheckBox and changing a Boolean variable
body: <p>So I have been trying to write a GUI using Python 3.3 and PyQt4. I have been through a few tutorials and I still can't figure out how to have a Checkbox checking and unchecking trigger change in a global variable. I can't get it to trigger anything for that matter because all the tutorials use methods that wont work for me.</p>
  
  <p>The program is too big to copy here as a whole so I have put together the basic structure of the program surrounding the Checkboxes</p>
  
  <pre><code>import sys
  from PyQt4 import QtGui, QtCore
  
  ILCheck = False
  
  class SelectionWindow(QtGui.QWidget):
      def __init__(self, parent=None):
          super(SelectionWindow, self).__init__(parent)
  
          ILCheckbox = QtGui.QCheckBox(self)
          ILCheckbox.setCheckState(QtCore.Qt.Unchecked)
  
          MainLayout = QtGui.QGridLayout()
          MainLayout.addWidget(ILCheckbox, 0, 0, 1, 1)
          self.setLayout(MainLayout)
  </code></pre>
  
  <p>This is where I'm stuck. What I want to do is change the state of ILCheck to True if the ILCheckbox is Checked and change it back to False when its Unchecked. Been working on this pretty much an entire day and none of the tutorials have been much help.</p>