my @rows;
my $z = @rows;  # There is nothing in @rows yet, so $z is 0
if ($z = 0) {   # but in any case, this will never return true!
print "We are sorry, but your search did not return any results.<P />\n";
print "<input type=\"button\" value=\"  Try again  \" onClick=\"history.go(-1)\">\n";
print "$tbl_ref\n";
}