case 'custom_attribute':
	$page = $contentObjectAttribute->content();
	$zone =& $page->getZone( $params[1] );
	$block =& $zone->getBlock( $params[2] );

	if ( !$http->hasPostVariable( 'BrowseCancelButton' ) )
	{
		if ( $http->hasPostVariable( 'SelectedNodeIDArray' ) )
		{
			$selectedNodeIDArray = $http->postVariable ('SelectedNodeIDArray' );

			$customAttributes[$params[3]] = $selectedNodeIDArray[0];
		}
		//check for other blocks that have browse option enabled and set their source node as well as this one. 
		$existing_custom_attributes = $block->attribute( 'custom_attributes' );
		$blocktype = $block->attribute( 'type' );
		if($existing_custom_attributes)
		{
			$blockini = eZINI::instance( 'block.ini' );
			$use_browse = $blockini->variable( $blocktype, 'UseBrowseMode');
			if($use_browse)
			{
				foreach($existing_custom_attributes as $custom_attr=>$attr_val)
				{
					if (isset($use_browse[$custom_attr])&&$use_browse[$custom_attr]=='true')
					{
						$customAttributes[$custom_attr] = $attr_val;
					}
				}									
			}
		}
		$block->setAttribute( 'custom_attributes', $customAttributes );
	}

	break;