Question:

I have a list with enabled and disabled option. I do know how to disable an option element but what I don't know how to enable it again.

<select size="1" id="x"> <option value="47" disabled="disabled">Value 47</option> ... selectElement.options[i].disabled = 'disabled'; // ... how to enable?

It should be done with Plain Javascript and no JavaScript Framework. (I wish I could use Prototype or a similar framework but I cannot introduce one of them.)

Use <a href="http://www.w3.org/TR/DOM-Level-2-Core/core.html#ID-F68F082" rel="nofollow">setAttribute</a> and <a href="http://www.w3.org/TR/DOM-Level-2-Core/core.html#ID-6D6AC0F9" rel="nofollow">removeAttribute</a>:

selectElement.options[i].setAttribute("disabled", "disabled"); selectElement.options[i].removeAttribute("disabled");

The DOM object's <em>property</em> is a boolean value, that should be set to true or false:

selectElement.options[i].disabled = false;

Also see <a href="https://stackoverflow.com/questions/706384/boolean-html-attributes" rel="nofollow">Boolean HTML Attributes</a>.