urlGeneration is used here for generating the link on the header.

<portal:urlGeneration contentNode="customUniqueName" portletWindowState="Maximized" layoutNode="7_2_6HD" portletMode="view">
<portal:urlParam name="view" value="customize" type="render"/>
<a href="<% wpsURL.write(out); %>">Link</a>
</portal:urlGeneration>

Attributes of urlGeneration
---------------------------
contentNode - The custom unique name of the page where the portlet resides
layoutNode - The portle ID. This can be easily taken from the generated html source, after the portlet is added to the page. Usually this will be within anchor tags like this <a name="7_2_6HD"></a>. Each portlet will have a different ID. We have to choose the right ID of our portlet.

Attributes of urlParam
----------------------
name - parameter name
value - value for this parameter
type - how this parameter will be accessed in the portlet like render parameter or action parameter

Once this parameter is available inside the portlet, use it to decide the flow(which page to include).