Passing values from partial to controller

Ruby
1

My partial:

        <p>
          <span title="Click to edit" id="edit_location">

<%= link_to grouprow.group_name %>

<%= custom_button('Change') %> 
        </p>
      </div>
<% form_tag (:controller => "users" , :action => "addfriendtogroups") do %> 
Add friend:

<%= text_field_with_auto_complete :user, ‘login’, {:size => 20},
{:tokens => ‘,’} %>

<%= hidden_field_tag :group_name ,grouprow.group_name %>
        <%= submit_tag "Add to group", :class =>

“submit_input_button rounded_corner” %>
<% end %>

</div>

My controller:

def addfriendtogroups
@f=User.find_by_login(params[:login])
@g=Group.find_by_group_name(params[:group_name])

@addfriend=GroupFriend.create(:user_id => current_user.id,
:group_id => @g.id,:friend_id => @f.id)

respond_to do |format|

if @addfriend.save

flash[:notice] = "Friend added to group successfully."

format.html {redirect_to :back}

end

end

end

I get the following error

RuntimeError in UsersController#addfriendtogroups

Called id for nil, which would mistakenly be 4 – if you really wanted
the id of nil, use object_id

Request

Parameters:

{“group_name”=>“testinggroup2”,
“commit”=>“Add to group”,
“authenticity_token”=>“MHB8Ys8vccsGwbgnsb9r5T68oqirPpW6YUscfDojZhY=”,
“id”=>“testing”,
“user”=>{“login”=>“santosh”}}

I need to fetch the id of login (santosh) from users table and id of the
groupname (testinggroup2) from groups and insert the userid, friendid
(id of santosh), groupid (id of testinggroup2) into another table.

Please help. Thanks.