The BO-Layer project should be saved before proceeding to the next step, the creation of an ASP.NET project.
method 1
Click the Save button 
(Save the current Project or Database Repository) on the Standard Toolbar.
method 2
Right-click the BO-Layer project in the Project Explorer and choose Save.
method 3
Choose Save Project from the File menu.
Hint:
Save the BO-Layer project file in the project directory that you created when saving your Database Repository.
At this point, you might go on to use the library of business objects that has been created in a standard software development project with Microsoft Visual Studio.NET 2005. The following topics describe how to do this:
Using Generated NHibernate DLL in WebForms
Using Generated NHibernate DLL in WinForms