inserting tags when using wp_insert_post

Hey guys,

I have been working on a blog space that i want to give the users the ability to add and edit posts for a psuedo-backend.. i have it adding and editing posts fine.. however, i have been told i need to implement tags into the posts and edits..

now i have it currently able to display the tags that are relevant to previous posts… but using my back end its not working to either edit them or add them

I have read through
http://codex.wordpress.org/Function_Reference/wp_insert_post
and it shows that you can add the ‘tags_input’ into the $posts array.. but then doesnt mention how you write $posts to the database..

my code looks like

[Code moderated as per the Forum Rules. Please use the pastebin]

now my understanding of why this is not working is that the $post_to_edit data that is being handed to wp_insert_post / wp_update_post is only dealing with the wp_posts database table…

does anyone know how i can add/edit tags to the database using wp_insert_post and wp_update_post??

Thank you in advance