Adding javascript to report

Hello everyone,

I want to ask you about how could i edit the print format in a report ?

For example i have item prices report and i want to add a little javascript in the report ( the current date ) and i didn’t find a way to edit the form except the head and the head could be added from the head letter… head letter options are image or html and javascript didn’t work…

the second question how could i find query report file in the erpnext file in my computer… i only found script reports… thank you all