Following what has been the calling card for SolidWorks 2010 the development team has consolidated another area of the software to make it 1 dialog box instead of multiple dialogs that you need to cycle through.

In the past when you would close an assembly or multiple documents you would need to go through multiple dialog boxes asking whether you would like to save each one or not.  Starting in SolidWorks 2010 this has all be put into a single dialog box as shown below.  This is just another way to save a little time when closing out of multiple documents or assemblies.

When you get to the above dialog you will have 3 options that you will be able to choose from; save all modified documents, selectively save modified top-level documents, or discard changes to all documents.

Also, if you do not like having to do this and would always like to save all modified documents or discard changes to all documents you can select the “Don’t as me again when saving” check box in the lower left hand corner to not be bothered with this dialog box again.  Remember, if you accidentally check this box you can turn it back on by checking it again in Tools > Options > System Options > Advanced.