You have to loop from 0 to i < colCount. In JavaScript, and many other language, the indexing starts from zero.

Look:

Loop through an array in JavaScript

you should declare a answer variable .and you should access "q1" elements by giving index since you have 3 "q1" elements .basically form.q1 is a object NodeList .you can't get value from object NodeList.so actually in your case you should add brake to for loop and find the clicked radio button index .

you should use

answer1 = form.q1[i].value;

instead of

answer1 = form.q1.value;

form.q1 is a object NodeList so

form.q1.value --> undefined since object NodeList/collection has no property "value"

and

form.q1[0] --> HTMLInputElement so

form.q1[0].value --> is not undefined 

fixed code .WORKING DEMO http://jsfiddle.net/madhawa11111/3rywkdvf/

function hp(form) {
    var i;
    var answer;
    var count1 = 0,count2 = 0,count3 = 0,count4 = 0,count5 = 0,count6 = 0,count7 = 0,count8 = 0,count9 = 0,count10 = 0, a;

    for (i = 0; i < 3; i++) {
        if (form.q1[i].checked === true) {
            count1++;
            break;
        }
    }
    if (count1 !== 1) {
        alert("Please Answer 1st Question");
        return false;
    }
    answer1 = form.q1[i].value; //error was here .
    a = Math.floor(answer1);
    document.getElementById("result").innerHTML = "The selected values are " + "</br>" + answer1;
}

if it worked in google chorm that's because browsers ignore some errors.

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