Sets or retrieves the state of an object for user interaction.
Disabled elements cannot have focus, do not receive or fire mouse events, cannot receive user input.
Disabled elements are rendered in gray by default in browsers.
All HTML elements that can have a direct or indirect effect on the visual appearance of the page, support the disabled property in Internet Explorer (except the option and optgroup elements before version 8).
In Opera, Firefox, Google Chrome and Safari, only the form controls support this attribute.
Another difference is that a disabled element is unselectable in Opera, Firefox, Google Chrome and Safari, while it can be selected in Internet Explorer.
You must set the unselectable property to 'on' to get this functionality in Internet Explorer.
If you only want to prevent the contents of the object from being changed, use the readOnly property instead of the disabled property.