try:
            os.stat("monitor")
        except OSError:
            # We cannot find monitor socket. So this machine might be
            # never run on this host
            f=open("start","r+")
            data=f.read()
            idx0=data.find("-net bridge,br=")
            idx=data.find("-net bridge,br=")
            if idx != -1:
                idx=data.find("=",idx)
                idx+=1
                idx2=data.find(" ",idx)
                bridgename=data[idx:idx2]
                if not bridgename in list_bridges():    
                    net = config.get("create options","net")