def OnOpenFile(self, event):
        """Request to open a new profile file"""
        dialog = wx.FileDialog(self, style=wx.OPEN|wx.FD_MULTIPLE)
        if dialog.ShowModal() == wx.ID_OK:
            paths = dialog.GetPaths()
            if self.loader:
                # we've already got a displayed data-set, open new window...
                frame = MainFrame()
                frame.Show(True)
                frame.load(*paths)
            else:
                self.load(*paths)
Request to open a new profile file