Resolve formatting differences between DB forge drivers
diff --git a/system/database/drivers/mssql/mssql_forge.php b/system/database/drivers/mssql/mssql_forge.php
index d2a30b2..3a3528f 100644
--- a/system/database/drivers/mssql/mssql_forge.php
+++ b/system/database/drivers/mssql/mssql_forge.php
@@ -151,7 +151,7 @@
 		return $sql.' '.$column_definition
 			.($default_value != '' ? ' DEFAULT "'.$default_value.'"' : '')
 			.($null === NULL ? ' NULL' : ' NOT NULL')
-			.($after_field != '' ? ' AFTER '.$this->db->protect_identifiers($after_field) : '');
+			.($after_field != '' ? ' AFTER '.$this->db->escape_identifiers($after_field) : '');
 	}
 
 }