问更改选择列表的Options数组？

$('element').options.length=0;
for (i=0; i<newSet.length; i++)
{
    $('element').options[i]=newSet[i];
}

/* get new options from json*/
var new_options = response.options;

/* Remove all options from the select list */
$('idresource').empty();
/* Insert the new ones from the array above */
for (var key in new_options)
{
var opt = document.createElement('option');
    opt.text = new_options[key];
    opt.value = key;
    $('idresource').add(opt, null);
}