Rails select tag with required true -

i have following select tag

<%= f.select :id, user.find(:all, :conditions => ["manager = ?", false]).collect {|u| [u.username, u.id]}, {:required => true}, {:class => "multiselect", :multiple => true} %> 

i try add :required => true it, view renders :required => true doesn't work!.

try this:

<%= f.select :id, user.find(:all, :conditions => ["manager = ?", false]).collect {|u| [u.username, u.id]}, {:multiple => true}, :class => "multiselect", :required => true %>