how to place this wpf dockpanel properly

Question

I'm trying to make a WPF DockPanel which looks like the following picture

However I'm a beginner to WPF and I cannot get it correctly. Here is what I'm trying to do.

<WebBrowser DockPanel.Dock="top" Loaded="abc" Name="webBrowser0" />
<WebBrowser DockPanel.Dock="left" Loaded="abc" width="200" Name="webBrowser2" />
<WebBrowser DockPanel.Dock="Right" Loaded="abc"  Name="webBrowser2" />
<WebBrowser DockPanel.Dock="Bottom" Loaded="abc" Name="webBrowser3" />