JavaScript simple cart - Fast Job

Avg Bid (USD)
Project Budget (USD)
$30 - $250

Project Description:
I have been working on this cart/pos and am now having problems with the javascript side of it

Job Description:

snippets of the code I need the work done on are attached
The 2 things I would like done are

QTY field when changed to use onchange function to update the other fields eg.(amount QTY price)

remove button - to complete this function (remove this item from cart (array))

No need to do anything else as I am still working on the rest it

the full file will be provided for you to work on

Skills required:
HTML, Javascript, PHP
Additional Files: sample.php
About the employer:
Public Clarification Board
Bids are hidden by the project creator. Log in as the employer to view bids or to bid on this project.
You will not be able to bid on this project if you are not qualified in one of the job categories. To see your qualifications click here.