$(element).prop('disabled', true); //true|disabled will work on all
$(element).attr('disabled', true);
element.disabled = true;
element.setAttribute('disabled', true);
var $element = $(...);
$element.prop('disabled', true);
$element.attr('disabled', true);
// The following do not require jQuery
$element.get(0).disabled = true;
$element.get(0).setAttribute('disabled', true);
$element[0].disabled = true;
$element[0].setAttribute('disabled', true);
var element = document.querySelector(".your-element-class-goes-here");
// it's a good idea to check whether the element exists
if (element != null && element != undefined) {
element.disabled = "disabled";
}