document shows you how to add a new config option and even section to the WebUI.
#### Update DB
Firstly you will need to add the config option to the database. Here's an example:
```sql
insert into config (config_name,config_value,config_default,config_descr,config_group,config_group_order,config_sub_group,config_sub_group_order,config_hidden,config_disabled) values ('alert.tolerance_window','','','Tolerance window in seconds','alerting',0,'general',0,'0','0');
```
This will determine the default config option for `$config['alert']['tolerance_window']`.