help with $_POST['fild'][$i]

[eluser]Marlon Souza[/eluser]
Hi guys, need helper to error in my loop, someone pass this, in applications normal php when have a array and can insert into database, I have a loop with for same this.

Code:

for($i=0; $1<=$limit; $i++){
$id_op=$_POST['fild'][$i];
      $this->Cars_model->insert($id_op);


}