How to call smartform FM after using SSF_FUNCTION_MODULE_NAME?

Hi Experts,

How to call smartform FM after using SSF_FUNCTION_MODULE_NAME?

I mean, in driver program i called SSF_FUNCTION_MODULE_NAME to get the related FM for my smart form. after that How do I call it(smartform fm) . I tried to call by pressing PATTERN button in Report. but it is showing FM is not exist error.

Call function SSF_FUNCTION_MODULE_NAME

Export

formname = 'zsmartform'

import

fm_name = function_name.

function_name is stored the corresponding smartform fm. then How do i call it to process my smartform?

thanks in advance.