single.phpの分岐

single.phpに下記を書く

<?php
$post = $wp_query->post;
if ( in_category('aaa') ) {
include(TEMPLATEPATH.'/single_aaa.php');
}
 elseif ( in_category('bbb') ) {
include(TEMPLATEPATH.'/single_bbb.php');
}
 elseif ( in_category('ccc') ) {
include(TEMPLATEPATH.'/single_ccc.php');
}
 elseif ( in_category('ddd') ) {
include(TEMPLATEPATH.'/single_ddd.php');
}
 else {
include(TEMPLATEPATH.'/single_normal.php');
}
?>