The buttons that we are using in the dialogs of RadWindow could not be skinned via RadFormDecorator, because they are not the standard input or button controls, but anchor tags with two nested SPAN elements.
We will talk to our designers to provide us with consistent designs for the buttons. In the meantime, you may easily modify the buttons in your project by giving style to the .radwindowbutton, .outerspan and .innerspan classes that the button consists of.
the Telerik team
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