Did a little clean up.  Nothing that affected functionality
diff --git a/system/database/DB_forge.php b/system/database/DB_forge.php
index cc88c32..d48165e 100644
--- a/system/database/DB_forge.php
+++ b/system/database/DB_forge.php
@@ -97,6 +97,16 @@
 	 */

 	function add_key($key = '', $primary = FALSE)

 	{

+		if (is_array($key))

+		{

+			foreach($key as $one)

+			{

+				$this->add_key($one, $primary);

+			}

+			

+			return;

+		}

+	

 		if ($key == '')

 		{

 			show_error('Key information is required for that operation.');