How can I find an option with a specific value using jQuery.find?

var prefix = document.getElementById("actionsum").value;
$('#actionsum')
    .find('option')
    .remove()
    .end()
    .append('<option value=""> </option>')
    .val('')
    .append('<option value="A0">A0</option>')
    .val('A0')
    .append('<option value="A1">A1</option>')
    .val('A1')
    .append('<option value="A2">A2</option>')
    .val('A2')
    .append('<option value="A3">A3</option>')
    .val('A3')
    .append('<option value="A4">A4</option>')
    .val('A4')
    .append('<option value="B0">B0</option>')
    开发者_如何学编程.val('B0')
    .append('<option value="B1">B1</option>')
    .val('B1')
    .append('<option value="B2">B2</option>')
    .val('B2')
    .append('<option value="B3">B3</option>')
    .val('B3')
    .append('<option value="B4">B4</option>')
    .val('B4')
    .append('<option value="LD">LD</option>')
    .val('LD')
    .attr("selected","selected")
    .append('<option value="SM">SM</option>')
    .val('SM')
    .append('<option value="SR">SR</option>')
    .val('SR')
    .find('<option value="'+prefix+'">'+prefix+'</option>')
    .attr("selected","selected");

Have you took a look at JQuery documentation on selectors? Especially the attribute equality selector.

$('#actionsum').find('option[value=B3]');

NOTE

You should take Konamiman's advice.