create post custom post type

Hi,

I can get all my custom post query by post_type=ad_listing.

Now I need to create a post but I have no idea how to create custom post since there is no post_type param in create_post function.

Please let me know is there any add on or customize controller?

Regards,
Alex

http://ww.wp.xz.cn/extend/plugins/json-api/