Call A Java Method From Javascript

I am trying to call a java method from within my Javascript, but cannot
seem to get it to work. All the examples I have found online and in
the forums are using Java applets. I have a method that I want to call
that does a search, and produces a message dialog displaying the
results. Also, the class file lives next to the html file. How would
I invoke this in my code? This is what I have now:

<script>
function searchStrings(){
Searcher.search();
}
</script>
<form>
<input type="button" value="Search" onclick=searchStrings()>
</form>