How do you add js to a record edit view in Sugar7?

before, I will wrote some js files and include them in editviewdef.php,and everything was fine,like 'displayParams' , $.ajax to get values .However ,when I fall in Sugar7,it seems that even I want to alert('hello') is a problem.

Now, I hope someone kind could give an method to include js file . specifically,in account ,I can use formula to make field A = filed B+ field C, but the field A can not be edit for using formula.I would use js to calculate it in th pass ,and certainly it could be edit .Now, how should I do?

Thanks