Setting a params hash to a variable within the controller (rails) - ruby-on-rails

Question

I'm very new to rails and have this fairly basic question:
I have a form that takes in an array:
<td><%= fields_for "days" do |form| %>
M: <%= form.check_box "", {}, 'M', '' %>
T: <%= form.check_box "", {}, 'T', '' %>
W: <%= form.check_box "", {}, 'W', '' %>
Th: <%= form.check_box "", {}, 'Th', '' %>
F: <%= form.check_box "", {}, 'F', '' %>
<% end %>
This should be accessible through params[:days]. How can I assign params[:days] to a variable within the controller? #days is not correct here, right? (There's no Days object, so there's no instance of that object). What should go in the [correct_variable] slot below?
[correct_variable] = params[:days]
Thanks!
In response to comments:
I tried using #days, but for some reason it wouldn't get called where I'd like it to. In particular, I'd like to pass it to my Search model:
class Search < ActiveRecord::Base
attr_accessible :name, :day, :units, :instructor
def courses
#courses ||= find_courses
end
private
def find_courses
Course.find(:all, :conditions => conditions)
end
def day_conditions
["courses.day LIKE ?", "%"+ #days.join("%")+"%"]
end
I first instantiate #days in my courses controller (which is connected, through the index method, to a partial that uses an instance of the Search object.
More code:
From courses/index.html.erb:
<% if #search.save %>
<div id = "results_scroll">
<%= render :partial => 'searches/search_results' %>
</div>
<% else %>
From search_results partial:
<% "Search" %>
<table>
<tr>
<th align="left" width="25%"><%= 'Name' %></th>
<th align="left" width="10%"><%= 'Number' %></th>
<th align="left" width="20%"><%= 'Instructor' %></th>
<th align="left" width="10%"><%= 'Room' %></th>
<th align="left" width="5%"><%= 'Day' %></th>
<th align="left" width="5%"><%= 'Units' %></th>
<th align="left" width="15%"><%= 'Time' %></th>
<th align="left" width="10%"><%= 'Limitations' %></th>
</tr>
<%= render :partial => #search_show.courses %>
</table>
From the courses controller (this has the #search_show variable).
def index
#courses = Course.order(sort_column + " " + sort_direction)
#search = Search.new
#search_show = Search.last
#title = "List"
#days = params[:days]
Finally, the _course.html.erb partial:
<tr>
<td><%= course.name %></td>
<td><%= course.number %></td>
<td><%= course.instructor %></td>
<td><%= course.room %></td>
<td><%= course.day %></td>
<td><%= course.units %></td>
<td><%= course.time %></td>
<td><%= course.limitations %></td>
<td><%= link_to 'Show', course %></td>
</tr>

Answer 1

This is not really an answer, but there is some problems with how you are trying to access your #days variable you set in the controller.
# your controller
...
def index
...
#days = params[:days]
# your model
...
private
def day_conditions
["courses.day LIKE ?", "%"+ #days.join("%")+"%"]
end
The #days, in your model, you are calling is not going to access the #days in your controller. Each #days belongs to their respective instances.
You should find a method of sending the #days from your controller into your models, instead of using global variables.

Answer 2

Solved the problem by using a $days global variable instead of #days.