Custom Script for static pages

Hi all,

I have this scenario in the context of POS:

I have 2 types of taxes applicable to items. I want the user to be able to select (from a Link field) which tax is applicable for each item when it is added to the list of items being sold. (This is similar to Quickbooks where the user selects the applicable tax from a dropdown). The tax type selected determines the amount of total tax calculated.
My questions are:

  1. Is it possible to write a custom script that will override the erpnext/public/js/pos/pos_bill_item.html thus allowing me to introduce the tax field? In other words, can custom scripts be written for Pages in addition to the DocTypes?. I know i can directly edit the HTML file but this is not recommended.
  2. Can the same custom script be used to extend (override) the calculation of taxes for the POS. If not, how do i ensure the javascript file is included in the POS page.

Its not possible to override the POS templates,

best to make this a contribution and send a pull request!

Thanks @rmehta