As is illustrated in Getting Started, it is not necessary to use a RadWindowManager object to create and use RadWindow controls. Using RadWindowManager, however, is a convenient way to declare common properties for all the windows your Web page brings up. When using RadWindowManager, you do not drag RadWindow objects onto your form directly from the toolbox. Instead, use the Windows property of the RadWindowManager control to bring up the RadWindow Collection Editor, where you can create the RadWindow controls and set their properties.
Both RadWindowManager and RadWindow inherit from RadWindowBase. The common properties that are set in RadWindowManager apply to all child RadWindow controls, and each individual RadWindow can override these with a new value. Typically, the RadWindow controls override the following properties:
VisibleOnPageLoad: Causes the window to be visible when the page is loaded. By default this value is false.
OffsetElementId: Indicates an HTML element whose upper left corner is used by the window to position itself when showing. This is commonly used in combination with the Top and Left properties.
InitialBehaviors: Specifies whether the window will be minimized or maximized initially (values can be added together - for example in addition you can specify whether to pin the windows).
Behaviors: Specifies whether the window can be maximized, minimized, resized, closed, and or pinned by the user.
While RadWindow objects do not require a RadWindowManager object, you must use RadWindowManager if you are making use of radalert , radconfirm , and radprompt dialogs. You will need the RadWindowManager as well if you want to use the radopen() function to open windows.