How do you remove all the options of a select box and then add one option and select it with jQuery?

$('#mySelect')
    .find('option')
    .remove()
    .end()
    .append('<option value="whatever">text</option>')
    .val('whatever')
;

$('#mySelect')
    .empty()
    .append('<option selected="selected" value="whatever">text</option>')
;

why not just use plain javascript?

document.getElementById("selectID").options.length = 0;