Looping action while button is pushed in Glade

[muppet]

I have written a script that runs with a glade gui. When a button in glade is pushed I need it to run a piece of code, pause for 3 seconds and run it again in an on going loop until the button is pushed again. So the button is just an on/off control.

I can get it to run the code with out any problems but i cannot get it to stop when the button is pushed again.

I have simplified the code for here,

from pylab import *
import sys
import datetime
import os
import time

import pygtk
pygtk.require("2.0")
import gtk
import gtk.glade


###############################################################################
# End of Imports 



record = 0
view = 0

class gui:

	def __init__(self):
		global record
		global view
				
               

		
                #Set the Glade file
                self.gladefile = "graph4a.glade"  
                self.wTree = gtk.glade.XML(self.gladefile) 
              
                #Create our dictionay and connect it
                dic = { "on_record_toggled" : self.record_toggle,
                        "on_window1_destroy" : gtk.main_quit }
                
		self.wTree.signal_autoconnect(dic)



		
        def record_toggle(self, widget):
		global record
		if (record == 1):
			print "Record is turned off"
			record = 0                        
						    
                else:
                        print "Record is turned on" 
			record = 1
			os.system("perl modbus3c.pl")   #These 2 lines need to be continually looped
			time.sleep(3)			#whenever the record button is toggled on
							#until it is toggled off again
	

if __name__ == "__main__":
        hwg = gui()
        gtk.main()