wordpress multiple categories

I want to display posts on homapage in following situations:

1. when "front_cat" is selecteded,
2. "front_cat" + one of other cats is selected(multiple cats selected in write panel)

in any other cases cats are not displayed in homepage, only in category page. tnx

Hope is not开发者_如何转开发 too confusing question.

I exluded categories from home page:

<?php
if ( is_home() ) {
  query_posts( 'cat=-13,-12,-15,-14,-7,-11,-6' );
}
?>

any ideas?