[Zope] why a xcatalog keywordindex is mandatory?

I've this in the form input of a zcatalog query: <tr><td>Collocazione AND</td> <td><textarea name="COLL2.query:lines:record" rows="3" cols="40"></textarea> <input type="hidden" name="COLL2.operator:record" value="and"> </td></tr> where COLL is a keywordindex. All works if I put something in the textarea. But if it is empty, it finds nothing instead of all, as other records. Help :) I've tried to change, in the form, COLL with COLL2 and do in the report script: <dtml-call "REQUEST.set('COLL',_['COLL2'])"> but it gives error (Error Type: TypeError Error Value: object has read-only attributes) ________________________________________________ Message sent using ALFANET Caorle WEBMAIL 1.0