sqlite trigger

I would like to have a trigger which should add up a counter by 1

this is my trigger which does not work.
CREATE TRIGGER insert_used AFTER INSERT ON body BEGIN UPDATE template SET used = used + 1 WHERE select_id = select_id

the where clause compares an ID from table ‘body’, and only for that ID it should add up the column used by 1,
but if it does it for all rows in table ‘template’. I tried with qualifying the select_id by saying WHERE select_id = body.select_id but it did not like the body.select_id.
How do I write this to get it working ?

found it,

I have to use … = new.select_id, that is working