Using SetTimeout() To Wait Until User Stops Clicking On A Group Of Checkboxes?

I have been working on a JS program that will, among other thing, allow users to search for downloads, articles, videos, etc, by selecting various checkboxes grouped under different fieldsets. Basically, when a user selects a checkbox, the pages sends an xhr request to the server and returns a specific set of search results at the bottom of the page. If the user selects a second checkbox in the same group, the previous results are deleted, and the new results are added to the page. The same happens when a user deselects a checkbox and there are other checkboxes within the same group that are still selected. The problem I run into is with real-world users who most likely will not be patient enough to wait for the results for the first checkbox to load before selecting a second checkbox. The result of this is that the server quickly becomes overloaded with requests, and old results are not deleted, or new results aren't even added properly. Basically, I would like to group the checkboxes in such a way that the browser waits until the user stops selecting or deselecting checkboxes before sending the request to the server.

As you can see from the code segment below, when the user selects a checkbox, a loop checks to see if any other checkboxes are selected, and then accordingly adds their values to an array. I have tried using setTimeout() to control how this works, but to no avail.

Code:
addResults: function(inputCheck)
{
// reference to keyword array created in the clickListener function
var keyword = GroupPlan.keyword;

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