Implemented insert_id() method
diff --git a/system/database/drivers/interbase/interbase_driver.php b/system/database/drivers/interbase/interbase_driver.php
index 8a156af..97bf722 100644
--- a/system/database/drivers/interbase/interbase_driver.php
+++ b/system/database/drivers/interbase/interbase_driver.php
@@ -341,12 +341,13 @@
 	 * Insert ID
 	 *
 	 * @access	public
+	 * @param  	string $generator_name
+	 * @param   integer $inc_by
 	 * @return	integer
 	 */
-	public function insert_id()
+	public function insert_id($generator_name, $inc_by=1)
 	{
-		//@todo Implement manually
-		return 0;
+		return ibase_gen_id($generator_name, $inc_by);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/user_guide_src/source/database/helpers.rst b/user_guide_src/source/database/helpers.rst
index 7ea19e9..e8a5ac8 100644
--- a/user_guide_src/source/database/helpers.rst
+++ b/user_guide_src/source/database/helpers.rst
@@ -7,9 +7,9 @@
 
 The insert ID number when performing database inserts.
 
-.. note:: If using the PDO driver with PostgreSQL, this function requires
-	a $name parameter, which specifies the appropriate sequence to check
-	for the insert id.
+.. note:: If using the PDO driver with PostgreSQL, or using the Interbase
+	driver, this function requires a $name parameter, which specifies the 
+	appropriate sequence to check for the insert id.
 
 $this->db->affected_rows()
 ===========================