Within the root of your website, create a file folder named scripts and create a shipping.js file

within it$.$

o This file will contain the JavaScript for this assignment.

o Code the $$()$ function at the top of the file

o Add an event handler for DOMContentLoaded

$$ Attach a function named calculate to the click event of the Calculate button

$$ Move focus to the product cost text box

o calculate function

$$ Parse the product cost

$$ Check to see if product cost is a valid number that is greater than zero

$$ If so$,$ pass the product cost to a function named calculateShipping

$$ If not, throw an alert with an appropriate message

$$ Leave focus on product cost

o calculateShipping function

$$ Accept product cost as a parameter

$$ The shipping cost will be calculated as a percentage of the product cost,

according to the following table:

Product Cost

Greater than Not greater than

Shipping Cost

Percentage

$05020\%$

$5020018\%$

$20050015\%$

$5001,00012\%$

$1,000$ xx $8\%$

$$ The function should return the sum of the product cost and the shipping cost