I\'m using ASP.NET MVC 3 with Razor views. When you want to create a view you can choose a layout (master page) for your view, or leave it to choose Default (_Layout).
I
In MVC3 you have _ViewStart.cshtml that stores all pages' Layout; you can change this element to change all pages' Layout or you can add new Layout element in top of target view pages in @{} block like the following to change the layout of the specific page:
@{
Layout = "~/Views/Shared/_newLayout.cshtml";
ViewBag.Title = "Index";
}