<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def OnSearch(self, event):
 """Event handler for starting the search"""


        search_string = self.search.GetValue()

        if search_string not in self.search_history:
            self.search_history.append(search_string)
        if len(self.search_history) > 10:
            self.search_history.pop(0)

        self.menu = self.make_menu()
        self.search.SetMenu(self.menu)

        search_flags = self.search_options + ["FIND_NEXT"]

        post_command_event(self, self.FindMsg, text=search_string,
                           flags=search_flags)

        self.search.SetFocus()