diff --git a/system/drivers/DB_mssql.php b/system/drivers/DB_mssql.php
index c842476..3fbfa6a 100644
--- a/system/drivers/DB_mssql.php
+++ b/system/drivers/DB_mssql.php
@@ -76,7 +76,7 @@
 	 * @param	string	an SQL query
 	 * @return	resource
 	 */	
-	function execute($sql)
+	function _execute($sql)
 	{
 		$sql = $this->_prep_query($sql);
 		return @mssql_query($sql, $this->conn_id);
@@ -97,6 +97,81 @@
     {
 		return $sql;
     }
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Begin Transaction
+	 * 
+	 * @access	public
+	 * @return	bool		 
+	 */	
+	function trans_begin()
+	{
+		if ( ! $this->trans_enabled)
+		{
+			return TRUE;
+		}
+		
+		// When transactions are nested we only begin/commit/rollback the outermost ones
+		if ($this->_trans_depth > 0)
+		{
+			return TRUE;
+		}
+
+		$this->simple_query('BEGIN TRAN');
+		return TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Commit Transaction
+	 * 
+	 * @access	public
+	 * @return	bool		 
+	 */	
+	function trans_commit()
+	{
+		if ( ! $this->trans_enabled)
+		{
+			return TRUE;
+		}
+
+		// When transactions are nested we only begin/commit/rollback the outermost ones
+		if ($this->_trans_depth > 0)
+		{
+			return TRUE;
+		}
+
+		$this->simple_query('COMMIT TRAN');
+		return TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Rollback Transaction
+	 * 
+	 * @access	public
+	 * @return	bool		 
+	 */	
+	function trans_rollback()
+	{
+		if ( ! $this->trans_enabled)
+		{
+			return TRUE;
+		}
+
+		// When transactions are nested we only begin/commit/rollback the outermost ones
+		if ($this->_trans_depth > 0)
+		{
+			return TRUE;
+		}
+
+		$this->simple_query('ROLLBACK TRAN');
+		return TRUE;
+	}
 	
 	// --------------------------------------------------------------------