def select_pop_up(self,windowID):
self.do_command("<STR_LIT>", [windowID,])<EOL>
Simplifies the process of selecting a popup window (and does not offer
functionality beyond what ``selectWindow()`` already provides).

*   If ``windowID`` is either not specified, or specified as
    "null", the first non-top window is selected. The top window is the one
    that would be selected by ``selectWindow()`` without providing a
    ``windowID`` . This should not be used when more than one popup
    window is in play.
*   Otherwise, the window will be looked up considering
    ``windowID`` as the following in order: 1) the "name" of the
    window, as specified to ``window.open()``; 2) a javascript
    variable which is a reference to a window; and 3) the title of the
    window. This is the same ordered lookup performed by
    ``selectWindow`` .



'windowID' is an identifier for the popup window, which can take on a                  number of different meanings