Inserting data into multiple tables

with codeigniter you have to create as many array as table you want to insert the data

this will be in your model

function addProductCategory($aProductCategory){
$this->db->insert('tbl_products_type',$aProductCategory);
}

this in in your controller

function insertProductCategory(){

$productCategory = array('product_type_name' => $this->input->post('txt_product_category'));

$this->mod_Product_Category->addProductCategory($productCategory);

}

you get the value from the view