<% form_tag url_for(:action => "update") do %>

Old Password
<%= password_field_tag "old_password", @old_password, :size => 45 %>

New Password
<%= password_field_tag "password", {}, :size => 45 %>
Between 4 and 40 characters

Confirm new password
<%= password_field_tag "password_confirmation", {}, :size => 45 %>

<%= submit_tag "Change password" %> <% end %>