fetching checkbox multidimensional array in javascript

Question

As per the requirement i have to create xhtml dynamically as described below

Answer 1

use this function:

function checkAll(obj){
    var element = [];
    var inputs = document.getElementsByTagName("input");
    for(var i = 0; i < inputs.length; i++)
    {
        if(inputs[i].name.indexOf('courses[' + obj.value + ']') == 0)
        {
           element.push(inputs[i]);
        }
    }

    if(obj.checked){
        for(i=0;i