How to get value of selected radio button?

Question

I want to get the selected value from a group of radio buttons.

Here\'s my HTML:

Answer 1

A year or so has passed since the question was asked, but I thought a substantial improvement of the answers was possible. I find this the easiest and most versatile script, because it checks whether a button has been checked, and if so, what its value is:

You can also call the function within another function, like this:

function doSomething() {
    getRadioValue('theRadioGroupName');
    if (rdValue == '10') {
        // do something
    }
    else if (rdValue == 'noRadioChecked') {
        // do something else
    }  
}