It’s actually doable with a workaround.
Put this code into your theme footer.php before the closing body tag: http://pastebin.com/raw.php?i=6hymZi4h
In that code change the
var searchPhrase = "";
line to the phrase you want to populate results from. For example if you want to have “test” automatically typed in, change it to:
var searchPhrase = "test";
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