How to I get the value of a radio button with javascript

Question

I need to obtain the value of a radio button using javascript

I have a radio group called selection

Answer 1

Although Matt's solution works perfectly fine and solves your immediate problem, I would also recommend that you start looking into a JavaScript library, like JQuery, if you will be frequently querying the DOM.

With JQuery, your solution is a one-liner:

var selectedValue = $("input[name=selection]:checked").val();

Answer 2

Use:

function getRadioValue(name) {
    var group = document.getElementsByName(name);

    for (var i=0;i<group.length;i++) {
        if (group[i].checked) {
            return group[i].value;
        }
    }

    return '';
}

Application:

var selectedValue = getRadioValue('selection');

Demo:

http://www.jsfiddle.net/tqQWT/