need to calculate after field data changed by radio button

Hi

i have a web page with too much code to post here. and i am having a hard time extracting a working sample.

basically, i have fields that result in an on-the-fly calculation. as the user works on the web page calcs are made prior to submission of the form

I use a radio button to toggle between two choices, and once i click on that, the relevant value infills two particular field

now the code to calculate works fine, but, and this is the reason for my post, only if the user manually inputs into a field, any one, it doesnt matter.

so even though my radio button code gets the desired data to fill in the awaiting fields, upon entry, the other field that is supposed to calculate the data in the fields the radio button brought in wont calculate, and i am trying to find the code so that when i click on the radio button, and the requested data fill in the field below, the calc filed will calculate without the user having to scroll up the page and manually enter a number somewhere just to trigger the calculation

here is the layout”

field a + field b
field c + field d

field e = field a + field c
field f = field b + field d

radio button copies :

field e to field i
field f to field j

then, finally,

field k = field i + field j

in this case, if i click on the radio button, the data falls in nicely, but it wont automatically calculate. Field K will remain blank

but once the radio button places the data in i and j, if i enter data in any of the other fields, field k calculates

how can i get it so that when i click on the radio button and the data hits the respective fields, how can i get it to calculate on that event?

thanks!

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