Return a value from an jQuery ajax function

I know there are a lot of questions regarding this but none of them seem to answer my particular question.

I'm having trouble constructing a function that includes an ajax call then returns a value. I am currently using:

    hmis_query_temp_scalar: function(query_name) {
        return $.ajax({
            url: '/php_scripts/query_temp_scalar.php',
            data: {query_name: query_name},
            async: false
        }).responseText
    }

but I would like to make it asynchronous, but if I change it to async: true It doesn't work, I just get undefined values. Is there any way of doing this?

The way I am currently using the function is as follows:

The page loads the following scripts:

$(document).ready(function() {
    $.setQueryLink('active_clients', '1');
    $.setQueryLink('active_clients_u18', '1');
    $.setQueryLink('active_clients_19_59', '1');
    $.setQueryLink('active_clients_o60', '1');
...

Which calls the following:

setQueryLink: function(query_name, type) {
        var object = "#" + query_name;
        var value = $.hmis_query_temp_scalar(query_name);

        $(object).html(value);
        $(object).attr('href', "/standard_queries.php?query=" + query_name + "&type=" + type);
    }

Is there a better way of doing this? (I know it seems like it should be done in PHP but that's not what I want at the moment, I want the 开发者_开发问答asynchronous loading behavior of javascript) I don't see any but are there any reasons why I can't run this asynchronously?

What you want to do is split them up... Provide a success function for your request to call when it returns, and then take action based on the response.

i.e.

$.ajax({
    type: 'POST',
    url: 'formService.asmx/RemoveFieldOption',
    contentType: 'application/json; charset=utf-8',
    data: "{'fieldId':'1', 'optionId':'1'}",
    dataType: 'json',
    success: action_removeFieldOptionPass,
    error: ajaxTestFail
});

function action_removeFieldOptionPass(result) {
    $('#whatever').html(result);
}