You need to keep writting to the browser. Here's a snippet from Jumble solver CGI that does that.

sub spelled {
    my $word = shift;
    my $out=`$speller $word`;
    chomp($out);
    if ( ($loopCount++ % 10) == 0 ) {
        print "." if ($charCount % 4) == 0;
        print "o" if ($charCount % 4) == 1;
        print "O" if ($charCount % 4) == 2;
        print "o" if ($charCount % 4) == 3;
        $charCount++;
        print "<BR>\n" if ($charCount % 29 ) == 0;
    }
    if ( length($out) > 0 ) {
        print "[$out]<BR>\n";
    }
}
[download]

the sub spelled gets called from the permute sub (which is not really the most effiecent way to solve jumbles but is useful for demostrating how to keep the browser from timing out) ... well the sub spelled writes to the browser via the calls to print ...

        print "." if ($charCount % 4) == 0;
        print "o" if ($charCount % 4) == 1;
        print "O" if ($charCount % 4) == 2;
        print "o" if ($charCount % 4) == 3;
[download]

I hope that helps.