reperire ID ancora non generato

[rocco.mod]

function AddNewThread($forumid,$title,$opened,$status,$levelforum,$displayorder,$urlredirect,$enabledbbc,$enabledsmiles,$enabledsignature ,$forumtext)
{
  global $dbcore,$RCW ;

     $result = $dbcore->query("INSERT INTO `forumpost` (`forumpostid`,`forumid`,`title`,`description`,`dateadd`,`dateedit`,`userid`,`opened`,`status`,`view` ,`countreplay`,`levelforum`,`displayorder`,`urlredirect`,`enabledbbc`,`enabledsmiles`,`enabledsignature` )VALUES( 
     NULL ,
     '". intval($forumid)."',
     '". $dbcore->escape($title)."',
     '',
     '". time()."',
     '',
     '".$dbcore->escape($RCW['user']['userid'])."',
     '".intval($opened)."',
     '".  intval($status)."',
     '0',
     '0',
     '".  intval($levelforum)."',
     '". intval($displayorder)."',
     '".$dbcore->escape($urlredirect)."', '".intval($enabledbbc)."', '".intval($enabledsmiles)."', '".intval($enabledsignature)."'
     )")or die(mysql_error());
     
     if(!$result){return false;}
     $insert_id    = $dbcore->insert_id();
 $res = $dbcore->query("INSERT INTO `forumpostdata` (`forumpostdataid`,`forumid`,`forumtext`,`dateadd`,`dateedit`,`userid`,`keypost` )
 VALUES( NULL, '". intval($insert_id)."','". $dbcore->escape($forumtext)."' ,'". time()."','','".$dbcore->escape($RCW['user']['userid'])."','1')")or die(mysql_error());    
 
      if(!$res){return false;}
 
      return $insert_id; 

} 

se invece di usare retur true metto return $insert_id come potrei recuperare l id da un altra funzione ! sto esaurendo e non ho ancora trovato una soluzione