How to implement “select all” check box in HTML?

Question

I have an HTML page with multiple checkboxes.

I need one more checkbox by the name \"select all\". When I select this checkbox all checkboxes in the HTML page must b

Answer 1

My simple solution allows to selectively select/deselect all checkboxes in a given portion of the form, while using different names for each checkbox, so that they can be easily recognized after the form is POSTed.

Javascript:

function setAllCheckboxes(divId, sourceCheckbox) {
    divElement = document.getElementById(divId);
    inputElements = divElement.getElementsByTagName('input');
    for (i = 0; i < inputElements.length; i++) {
        if (inputElements[i].type != 'checkbox')
            continue;
        inputElements[i].checked = sourceCheckbox.checked;
    }
}

HTML example:

All of them

    
Spacey, Kevin
    
Firth, Colin
    
Johansson, Scarlett

I hope you like it!