Probably you're gonna loose your job...

Something like
# Search specific fields only
my $searchonly = $in{'searchonly'};

if ($searchonly eq "all") {
@search_fields = (1,2,5,14);
}
if ($searchonly eq "title") {
push @search_fields, 1;
}
if ($searchonly eq "description") {
push @search_fields, 5;
}
if ($searchonly eq "url") {
push @search_fields, 2;
}
if ($searchonly eq "stichworte") {
push @search_fields, 14;

Test it.
Ciao
Denis