Do you need a custom web part to add validation to an OOB PDP? For example I have the OOB project details page I want to add validation to the save button to ensure a value entered is not a dupe.
I've been referencing this blog post: http://blogs.msdn.com/b/husainzgh/archive/2011/08/01/hooking-into-the-project-detail-page-ribbon-save-button-without-overriding-out-of-box-functionality-in-project-web-access-for-project-server-2010.aspx