thanks your reply: 
   can i use the next code:
  1 :  use   api = switch_loadable_module_get_api_interface(cmd) .  get the application's API .

  2 :   run : api->function(arg, session,stream)
  
  is the above is correct ? 
 
   thank you very much !

2009/9/11 Michael Jerris <mike@jerris.com>

We don't allow calling functions between modules.  You can look at the
api interface for a way to trigger things between modules or possibly
the event system.

Mike

On Sep 11, 2009, at 1:30 AM, daqiang wang wrote:

> hello :
>    How can i to call the funciton in another module ?
> example:
>   I want to add code in mod_voicemail. to call rxfax. the function
> of mod_fax .
>   what's the step to do ?
>  thanks .