This question has been answered by coroico. See the first response.
$_lang['advsearch.no_results'] = '<span class="flash">There were no search results. Please try using more general terms to get more results.</span>';
In $_lang['advsearch.no_results'] I need something like this: "There were no search results for [[+text]]. Please try using more general terms to get more results."[/s]
But [[+text]] doesn't work here. How can I get request in advsearch.no_results?
As specified in the documentation, did you try to use [[+searchValue]] instead of [[+text]] ?