In your online demo, there is only a masterpage example with Web Splitter. Does WebDock also support master page? I tried with the following code, but i was unable to edit the ContentPlaceHolder in the design view of a child page. The entire page was greyed.
<%@ Master Language="C#" AutoEventWireup="true" CodeBehind="Site2.master.cs" Inherits="Testing.Site2" %>
<%@ Register Assembly="ZettaCube.ZeeControls" Namespace="ZettaCube.ZeeControls" TagPrefix="cc1" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<cc1:WebDock ID="WebDock1" runat="server" Height="479px" Width="748px" FitParent="FitWindow">
<MainContent>
<asp:ContentPlaceHolder ID="ContentPlaceHolder1" runat="server">
</asp:ContentPlaceHolder>
</MainContent>
<Panels>
<cc1:WebDockPanel runat="server">
<Tabs>
<cc1:WebDockTabbedPanel runat="server">
</cc1:WebDockTabbedPanel>
<cc1:WebDockTabbedPanel runat="server">
</cc1:WebDockTabbedPanel>
</Tabs>
</cc1:WebDockPanel>
</Panels>
</cc1:WebDock>
</div>
</form>
</body>
</html>