Bug 156084 __bookmark doesn't work in pdf with frameset servlet
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/service/ViewerHTMLActionHandler.java
{
		if ( actionDefn == null )
			return null;
		switch ( actionDefn.getType( ) )
		{
			case IAction.ACTION_BOOKMARK :
			{
				return buildBookmarkAction( actionDefn, context );
			}
			case IAction.ACTION_HYPERLINK :
			{
				return actionDefn.getActionString( );
			}
			case IAction.ACTION_DRILLTHROUGH :
			{
				return buildDrillAction( actionDefn, context );
			}
		}
		return null;
	}
	/**
	 * Build URL for bookmark.
	 * 
	 * @param action
	 * @param context
	 * @return the bookmark url
	 */
	protected String buildBookmarkAction( IAction action, IReportContext context )
	{
		if ( action == null || context == null )