Force all visits to a site to https

Is there a way to make all the visit to a site be https instead of http even when the admin is visiting the manager? If the manager is saving a resource in the http://www.domain.com/manager all the cache is created for http and not https. I want something, perhaps some .htaccess code to automatically change it over to https if the visitor is only typing www.domain.com (or www.domain.com/manager) in the url-field.

perhaps some .htaccess code

You already know most of the answer - Google will provide the rest!

Perhaps the .htaccess code outlined here: http://rtfm.modx.com/display/revolution20/Hardening+MODX+Revolution#HardeningMODXRevolution-ForcingSSLconnectionstotheManager