Re: Checkbox to calculate if fee is applied or not

I'm not certain the Adobe Express forum is the place for this? We don't use javascript for creating projects. Unless this is for Add-On development? There is a channel in the Adobe Express Discord for that if so, and they may be able to help. 
https://discord.gg/adobeexpress

in the future, to find the best place to post your message, use the list here, https://community.adobe.com/

p.s. i don't think the adobe website, and forums in particular, are easy to navigate, so don't spend a lot of time searching that forum list. do your best and we'll move the post (like this one has already been moved) if it helps you get responses.

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I am trying to learn the best way to write the javascript to apply a fee to the subtotal if the checkbox is selected. 

Here is the situation

If we have a subtotal and the person wants to pay by Credit Card we will need to add a 3% credit card fee. So the checkbox is clicked if they are paying by credit card. The subtotal multiplied by the credit card fee would then become the grand total.