The file object content for ASP is based on a special template called DefaultContent defined with respect to the FileObject metaclass. It is located in the Profile/FileObject/Criteria/ASP/Templates category of the C# and VB.NET object languages. This link to the template exists as a basis, therefore if you edit the file object, the link to the template is lost - the mechanism is similar to that of operation default bodies.
For more information on the Criteria category, see "Criteria (Profile)", in the Extending your Models with Profiles chapter of the Customizing and Extending PowerDesigner manual.
Active Server Page files are identified using the ASPFile stereotype. The server page name is synchronized with the ASP.NET component name following the convention specified in the Value box of the Settings/Namings/ASPFileName entry of the C# and VB.NET object languages.
You can right-click a file object, and select Open With→ text editor from the contextual menu to display the content of the file object.