How do I use Jquery to find and select a Multi Select option by the Value?

Question

I can't seem to figure out how to correctly select a Multi Select option by the Value and leave the other options that are selected alone.

Update It does work, thanks! I had the multi-select hidden and I thought firebug would update the option to "selected" but it doesn't. When I "show" the multi-select box after setting the attr to selected, it was selected. So that was also part of my problem, what firebug was showing me behind the scene.

Answer 1

To select an individual option, leaving the rest alone:

$("#selectID option[value='" + myValue + "']").attr('selected', 'selected');

Or, alternatively since .val() returns an Array in the multiselect case:

var vals = $("#selectID").val();
vals.push(myValue);
$("#selectID").val(vals);