[TYPO3] Run PHP code into a plugin in the BE

[Francesco Pessina]

Hi to everyone,

I want to run some PHP code in my plugin (created by kickstater) in the 
BE/FE when the user create a new record or modify an exsisting (record) 
of data owned by the same plugin (installed as content in a page).

Which file of the plugin I have to edit for make this trick?

Thanks a lot,

Francesco.