Dynamic HTML: The Definitive Reference

Name

CHECKED — NN 4 IE 3 HTML 4

Synopsis

CHECKED

Optional

A Boolean attribute that designates whether the current checkbox or radio INPUT element is turned on when the page loads. In the case of a radio button grouping, only one INPUT element should have the CHECKED attribute. Scripts can modify the internal value of this attribute after the page has loaded. When the form is submitted, an INPUT element whose CHECKED attribute is turned on sends its name/value pair as part of the form data. The name/value pair consists of values assigned to the NAME and VALUE attributes for the element. If no value is assigned to the VALUE attribute, the string value "active" is automatically assigned when the checkbox or radio button is highlighted. This is fine for checkboxes because each one should be uniquely named. However, all radio buttons in a related group must have the same name, so this default behavior doesn’t provide enough information for most server-side programs to work with.

Input Types

checkbox, radio

Example

<INPUT TYPE="checkbox" NAME="addToList" CHECKED>Send email updates to this 
web site.

Value

The presence of this attribute turns on its property.

Default

Off.

Object Model Reference

NN

[window.]document.formName.inputName.checked

[window.]document.forms[i].elements[i].checked

IE

[window.]document.formName.inputName.checked

[window.]document.forms[i].elements[i].checked

[window.]document.all.elementID.checked