Login box on one site to log you into another site too My client has a drupal 6 site. This is used with there clients to project manage projects. We are building a new main website for our client using drupal (6/7 yet to be decided). They wish to have a login box on the home page of there new website that will log you into the project manage site. So something like:

Go to main website
Enter user name and password for project site
Website changes to project site with user logged in.

Would this be possible? The user would not have a login on the main site.

Both sites would be running on the same machine. Part of me is thinking that maybe multi-site could be my answer.
Sure it's possible. There are many ways to do this.

A simple solution, if both sites are running the same drupal version, would be to make a custom form, and connect to the other sites database, and get the login form. You would need to make sure that the submit path would go to the project manage site.

When the form is submitted, they would automatically go the that site, and if user/pass is correct, they would also be logged in.

Disclaimer: I haven't actually tried this before, but it should work just fine. Drupal wont know where the form was submitted, so should be the same as being on their project site and using the login form.