Question

Does anyone know of a simple example of showing / hiding a div when one of two select dropdown options are selected? I’d like to keep it simple and not have to use plugins with the exception of jquery which is already loading.

Answer 1

you could use the following function which shows the passed element if the dropdown have the values 12 and 22 (you can change it to whatever you need):

function showDiv(element, firstDropdown, secondDropdown) {
    firstDropdown.children("option:selected").val() == 12 && secondDropdown.children("option:selected").val() == 22 ? element.show() : element.hide();
}

then in jQuery you can write the following:

var myElement = $("div");
var myFirstDropdown = $("select#first");
var mySecondDropdown = $("select#second");

$("select").change(function() {
    showDiv(myElement, myFirstDropdown, mySecondDropdown)
});

Demo: http://jsfiddle.net/ERS9D/