webrfc is not working

Hi persona gurus,

right now we are using SAP PERSONA's version 1.0 with sp04.

when i tried in the system to create WEBRFC and  follow the same steps suggested in the below blog  call the function module as mentioned in the below Blog.I've checked the function module in SMW0 and found that it is released to internet.

WebRFC - simply calling an RFC from javascript.

i am getting below Error:

Parameter _FUNCTION is missing or written incorrectly in www_DISPATCH_REQUEST.

do i miss any other steps to get this Done.

Please suggest!!

Thanks in Advance.

Regards,

Sudarsan.S