how to enter and update difeerent tables data from views ?

hi ,

i have two tables called streams and tags.
using tags table i am assigning tags to the stream table entries using
acts_as_taggable plugin.
Now problem is if i try to enter the data for tag table in
new.html.erb file from views/streams getting error like

Couldn't find Stream without an ID problem

i have tried to enter data in new.html.erb file like:
      <p>
       <b>Tags</b><br />
       <%= f.text_area('tags_as_text') %>
       </p>

instead if i use below code in views:

<p>
       <b>Tags</b><br />
       <%= text_field_tag 'tag_list', @stream.tags.collect { |tag|
tag.name.include?(" ") ? '"' +"#{tag.name}" + '"' : tag.name }.join("
")%>
     </p>

i am able to enter data but it is not reflecting in tag table and not
showing if i do the show option provided .

how to solve this problem?

thanks for any help or suggestions?

regards
Srikanth