You can use jQuery to find the option element in all other dropdowns (in my example, designated by a certain class...and can easily be changed to another selector - I thought the selector "select" was too broad), and then disable the actual option element by using .prop("disabled", true). But it's a little more tricky than this, as you need to keep track of the previous selected value to enable the dropdown again when a different value is chosen. Here's an example that will hopefully help:
http://jsfiddle.net/p5Arj/
$(document).ready(function () {
$(".test").each(function () {
var $self = $(this);
$self.data("previous_value", $self.val());
});
$(".test").on("change", function () {
var $self = $(this);
var prev_value = $self.data("previous_value");
var cur_value = $self.val();
$(".test").not($self).find("option").filter(function () {
return $(this).val() == prev_value;
}).prop("disabled", false);
if (cur_value != "") {
$(".test").not($self).find("option").filter(function () {
return $(this).val() == cur_value;
}).prop("disabled", true);
$self.data("previous_value", cur_value);
}
});
});
So this disables all other dropdowns' same options when you choose one, and makes sure that when you choose another, the previous one is enabled in all other dropdowns. For example, choose "3" in the first dropdown...look at the second dropdown - see that "3" is disabled...go back to the first dropdown and choose "1"...look at the second dropdown - see that "3" is enabled again but "1" is disabled. That's what the use of .data is for in my code.
Of course, you can replace the use of value with selectedIndex if you are 100% sure that all of the options will be the same for each select in question.