I'd like to include the search form on my index page.
I've read the user guide and the forum, but I can't figure out how to include
the result page on a pseudo frame.
I'd like, when I click the search button on the form of the main page, to get the result inside the same page.
My website is structured with PHP pseudo frames (if I click on a link, the appears on the same page maintaining all the menus and others parts around)
but if I put "http://mysite/index.php?rub=./search.php&zoom_query=$zoom_query" on the form (on the action part), it doesnt work.
I don't know how to do, each time I type a keyword and click the search button, I go to "http://search.php?zoom_query=test" and not "index.php?rub=./search.php&zoom_query=test
I am not sure if there is really such a thing as a 'pseudo frame'.
You are either using frames with the <FRAMESET> tag or your not.
The default behaviour is for the search results to replace the current page. So by the sounds of it the default behaviour is what you want.
If you want to have your own custom headers and footers on your search results page you should edit the search_template.html file to add HTML code above and below the results.
If you want to have PHP code generate your headers and footers around the search results refer to this FAQ question,
I don't know what your index.php file does nor what parameters it expects and so can't really comment on it.
Note that if you're referring to inline frames (ie. <IFRAME>), they work the same way as a normal frameset so you can use the target= attribute to load the search page within a certain frame.
See this FAQ for more information on using Zoom on a frames-based website:
Wrensoft Web Software
Zoom Search Engine