public function previous()
    {
        $this->_itemValid = true;

        if (!prev($this->_items)) {
            $this->_itemValid = false;
        } else {
            $this->_itemPosition--;
        }
    }
public function previous()
    {
        $this->_itemValid = true;

        if (!prev($this->_items)) {
            $this->_itemValid = false;
        } else {
            $this->_itemPosition--;
        }
    }
public function previous ( ) { $ this -> _itemValid = true ; if ( ! prev ( $ this -> _items ) ) { $ this -> _itemValid = false ; } else { $ this -> _itemPosition -- ; } }
set previous item as current item

@return    void
set previous item as current item