Qt Designer 4.4.1 Signals and Slots

hi, this is my first try with PyQt so i'm trying to get a simple app to work with 1 button and 1 textbox. I tried many ways till finally get the UI to display correctly, but now i don't know where or how to define the behaviour of the button. I got the Signal/Slot thing to work with the Exit option in the menubar, but how do i define other behaviour not present in the Signal/Slot Edition window? (i think that dissapeared after Qt Designer 3.x).
Other Questions:
1.- What to define in the subclass? Controls (button, linEdit, combobox)? or Methods (on_button_clicked)?
2.- How?? (Qobjedt.connect......??)
3.- Here is my code...the main idea is just to get some text to the textbox on button_clicked(). I've read many PyQt Documentation, the reference guide, old versions docs, etc. I guess i'm the problem :crying:.

Code:

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import sys
from PyQt4.Qt import *
 
from ui import Ui_Main        
 
#this is the subclass that processes idk what rlly.... :confused:
class MainWindow(QMainWindow):
 
   def __init__(self, win_parent = None):
      QMainWindow.__init__(self, win_parent)
 
   #I don't think this on_boton_clicked it's correct, but it does work....:o
   def on_Boton_clicked(self):
      print "Clicked"
 
if __name__ == '__main__':
   app = QApplication(sys.argv)
   window = MainWindow()  
   ui = Ui_Main()
   ui.setupUi(window)
   window.show()
   sys.exit(app.exec_())
app.exec_loop()

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TY in Advance.

kk, so as i was drowning in a cup of water, here is the code if ne noob like me needs it.

Code:

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import sys
 
from PyQt4.Qt import *
#from PyQt4 import QtGui
#from PyQt4.QtCore import *
 
from ui import Ui_Main
 
def prueba():
  print 'as'
  ui.lineEdit.clear()
 
class MainWindow(QMainWindow, Ui_Main):
 
  def __init__(self):
      QMainWindow.__init__(self)
      print 'asd'
 
  def on_button_clicked(self):
      print 'pega'
      ui.lineEdit.paste()
 
  def on_limpia_clicked(self):
      print 'limpia'
      prueba()
      #ui.lineEdit.clear()
 
if __name__ == '__main__':
  app = QApplication(sys.argv)
  ui = Ui_Main()
  window = MainWindow()  
  ui.setupUi(window)
  window.show()
  sys.exit(app.exec_())
app.exec_loop()

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