<script>
    function myFunction() {

        document.getElementById("product-category").click();

        document.getElementById(“product-category”).value =
        array_productcategoryid.join(“|”);
    }
</script>

$this->load->DIR_TEMPLATE .
'journal2/template/account/customerpartner/addproduct.tpl';

$array_produtos = explode(“|”, $_POST["product-category"]);