JAVASCRIPT

jquery change selected option

$('select option[value=8272]').attr('selected', '');

jquery set select value

$("div.id_100 select").val("val2");

change value on selected jquery

<select onchange="getval(this);">
    <option value="1">One</option>
    <option value="2">Two</option>
</select>
 Run code snippet

change value on selected jquery

function getval(sel)
{
    alert(sel.value);
}