为自定义送货模块添加导入表速率csv功能

Question

i make new custom shipping module for magento shipping, just wondering actually how to make import csv function in main website, Thanks

            <import translate="label">
                <label>Import</label>
                <frontend_type>import</frontend_type>
                <backend_model>jne_adminhtml/system_config_backend_shipping_mycarrier</backend_model>
                <sort_order>40</sort_order>
                <show_in_default>0</show_in_default>
                <show_in_website>1</show_in_website>
                <show_in_store>0</show_in_store>
            </import>



   class MyCustomization_MyCarrier_Model_Adminhtml_System_Config_Backend_Shipping_MyCarrier extends Mage_Core_Model_Config_Data
    {
        public function _afterSave()
        {
            Mage::getResourceModel('mycarrier_shipping/carrier_mycarrier')->uploadAndImport($this);
        }
    }