following this tutorial  on wxpython, i've noticed in find/replace dialog example there panels doesn't seem they're doing anything. in fact, seem mess more layout (though mistake made somewhere) example, tutorial has code:   panel = wx.panel(self, -1)  panel1 = wx.panel(panel, -1) grid1 = wx.gridsizer(2, 2) grid1.add(wx.statictext(panel1, -1, 'find: ', (5, 5)), 0,  wx.align_center_vertical) grid1.add(wx.combobox(panel1, -1, size=(120, -1))) grid1.add(wx.statictext(panel1, -1, 'replace with: ', (5, 5)), 0, wx.align_center_vertical) grid1.add(wx.combobox(panel1, -1, size=(120, -1)))  panel1.setsizer(grid1) vbox.add(panel1, 0, wx.bottom | wx.top, 9)   why different from:   panel = wx.panel(self, -1)  grid1 = wx.gridsizer(2, 2) grid1.add(wx.statictext(panel, -1, 'find: ', (5, 5)), 0,  wx.align_center_vertical) grid1.add(wx.combobox(panel, -1, size=(120, -1))) grid1.add(wx.statictext(panel, -1, 'replace with: ', (5, 5)), 0, wx.align_center_ver...