Index: install/install_schema.sql
===================================================================
--- install/install_schema.sql	(revision 14635)
+++ install/install_schema.sql	(working copy)
@@ -800,6 +800,8 @@
   `Status` tinyint(4) NOT NULL DEFAULT '2',
   TextFormat int(11) NOT NULL DEFAULT '0',
   Module varchar(255) NOT NULL DEFAULT '',
+  HelpfulCount int(11) NOT NULL,
+  NotHelpfulCount int(11) NOT NULL,
   PRIMARY KEY (ReviewId),
   KEY CreatedOn (CreatedOn),
   KEY ItemId (ItemId),
Index: install/upgrades.sql
===================================================================
--- install/upgrades.sql	(revision 14636)
+++ install/upgrades.sql	(working copy)
@@ -2142,3 +2142,7 @@
 ALTER TABLE Skins ADD DisplaySiteNameInHeader TINYINT(1) NOT NULL DEFAULT '1';
 
 DELETE FROM PersistantSessionData WHERE VariableName LIKE 'formsubs_Sort%' AND VariableValue = 'FormFieldId';
+
+ALTER TABLE ItemReview
+	ADD HelpfulCount INT NOT NULL ,
+	ADD NotHelpfulCount INT NOT NULL;
Index: kernel/db/cat_event_handler.php
===================================================================
--- kernel/db/cat_event_handler.php	(revision 14644)
+++ kernel/db/cat_event_handler.php	(working copy)
@@ -33,6 +33,7 @@
 			'OnCancelAction' => Array ('self' => true),
 			'OnItemBuild' => Array ('self' => true),
 			'OnMakeVote' => Array ('self' => true),
+			'OnReviewHelpful' => Array ('self' => true),
 		);
 
 		$this->permMapping = array_merge($this->permMapping, $permissions);
@@ -2793,6 +2794,43 @@
 	}
 
 	/**
+	 * Marks review as useful
+	 *
+	 * @param kEvent $event
+	 * @return void
+	 * @access protected
+	 */
+	protected function OnReviewHelpful(&$event)
+	{
+		$review_id = (int)$this->Application->GetVar('review_id');
+
+		if ( !$review_id ) {
+			return;
+		}
+
+		$spam_helper =& $this->Application->recallObject('SpamHelper');
+		/* @var $spam_helper SpamHelper */
+
+		$spam_helper->InitHelper($review_id, 'ReviewHelpful', strtotime('+1 month') - strtotime('now'));
+
+		if ( $spam_helper->InSpamControl() ) {
+			return;
+		}
+
+		$field = (int)$this->Application->GetVar('helpful') ? 'HelpfulCount' : 'NotHelpfulCount';
+
+		$sql = 'UPDATE ' . $this->Application->getUnitOption('rev', 'TableName') . '
+				SET ' . $field . ' = ' . $field . ' + 1
+				WHERE ' . $this->Application->getUnitOption('rev', 'IDField') . ' = ' . $review_id;
+		$this->Conn->Query($sql);
+
+		if ( $this->Conn->getAffectedRows() ) {
+			// db was changed -> review with such ID exists
+			$spam_helper->AddToSpamControl();
+		}
+	}
+
+	/**
 	 * [HOOK] Allows to add cloned subitem to given prefix
 	 *
 	 * @param kEvent $event
Index: units/reviews/reviews_config.php
===================================================================
--- units/reviews/reviews_config.php	(revision 14590)
+++ units/reviews/reviews_config.php	(working copy)
@@ -162,6 +162,8 @@
 		    	'not_null' => 1, 'default' => 0,
 			),
 		    'Module' => Array ('type' => 'string', 'not_null' => 1, 'default' => ''),
+			'HelpfulCount' => Array ('type' => 'int', 'not_null' => 1, 'default' => 0),
+			'NotHelpfulCount' => Array ('type' => 'int', 'not_null' => 1, 'default' => 0)
 		),
 
 		'VirtualFields' => Array (
@@ -189,6 +191,8 @@
 					'CreatedOn' => Array ('filter_block' => 'grid_date_range_filter', 'width' => 145, ),
 					'Status' => Array ('filter_block' => 'grid_options_filter', 'width' => 80, ),
 					'Rating' => Array ('filter_block' => 'grid_options_filter', 'width' => 80, ),
+					'HelpfulCount' => Array ('title' => 'la_col_HelpfulCount', 'filter_block' => 'grid_range_filter'),
+					'NotHelpfulCount' => Array ('title' => 'la_col_NotHelpfulCount', 'filter_block' => 'grid_range_filter'),
 				),
 			),
 
@@ -206,6 +210,8 @@
 					'CreatedOn' => Array ('filter_block' => 'grid_date_range_filter', 'width' => 145, ),
 					'Status' => Array ('filter_block' => 'grid_options_filter', 'width' => 80, ),
 					'Rating' => Array ('filter_block' => 'grid_options_filter', 'width' => 80, ),
+					'HelpfulCount' => Array ('title' => 'la_col_HelpfulCount', 'filter_block' => 'grid_range_filter'),
+					'NotHelpfulCount' => Array ('title' => 'la_col_NotHelpfulCount', 'filter_block' => 'grid_range_filter'),
 				),
 			),
 		),
Index: units/reviews/reviews_tag_processor.php
===================================================================
--- units/reviews/reviews_tag_processor.php	(revision 14628)
+++ units/reviews/reviews_tag_processor.php	(working copy)
@@ -43,6 +43,18 @@
 		return $this->Application->HREF($edit_template,'', $url_params);
 	}
 
+	function HelpfulLink($params)
+	{
+		$object =& $this->getObject($params);
+		/* @var $object kDBItem */
+
+		$parent_prefix = $this->Application->getUnitOption($this->Prefix, 'ParentPrefix');
+		$params['events[' . $parent_prefix . ']'] = 'OnReviewHelpful';
+		$params['review_id'] = $object->GetID();
+
+		return $this->Application->ProcessParsedTag($parent_prefix, 'ItemLink', $params);
+	}
+
 	/**
 	 * Get's reuested field value
 	 *