Visual InterDev
When you save a site diagram, Site Designer updates the site structure file for the Web application with your changes. All pages in the project that have navigation bars will have their navigation bar links updated as well. Any pages you add to the site diagram with the New HTML Page or New ASP Page command are automatically created and added to the current project.
Note You can save changes to site diagrams in master and local modes only. You cannot edit or save a site diagram in offline mode.
To save a site diagram
The site diagram is saved with a .wdm file extension in the current Web application. The modified page icon is removed from the pages you edited in the diagram.
Caution If another user has made changes to the site that conflict with the site diagram you are trying to save, your changes may not be saved. Instead, an error message will appear, detailing the site structure file conflicts.