javascript question?

Question

I've wrote this script to average for number that user enters . but it doesn't work properly . plz help me with this . here's the script :
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showing the return

Answer 1

here's your problem

let's say you have a=1, b=2, c=3, d=4 as you input them in the "prompt"
when you add them a+b+c+d the result will be "1234" (a string) instead of 10 ( a number)

so do it like this

function average(a,b,c,d){
av=(parseInt(a) + parseInt(b) + parseInt(c) + parseInt(d)) / 4;
return av;
}

Answer 2

man I dont have time for this find out for yourself

http://www.google.co.uk/search?hl=en&q=javascript+script+to+average+for+number+that+user+enters&btnG=Search&meta=