[jquery] Trigger an action after selection select2

I am using select2 library for my search.
is there any way to trigger an action after selecting a search result? e.g. open a popup, or a simple js alert.

$("#e6").select2({
    placeholder: "Enter an item id please",
    minimumInputLength: 1,
    ajax: { // instead of writing the function to execute the request we use Select2's convenient helper
        url: "index.php?r=sia/searchresults",
        dataType: 'jsonp',
        quietMillis: 3000,
        data: function (term, page) {
        return {
            q: term, // search term
            page_limit: 10,
            id: 10
            };
        },
        results: function (data, page) { // parse the results into the format expected by Select2.
            // since we are using custom formatting functions we do not need to alter remote JSON data
            return {results: data};
        },
    },

    formatResult: movieFormatResult, // omitted for brevity, see the source of this page
    formatSelection: movieFormatSelection, // omitted for brevity, see the source of this page
    dropdownCssClass: "bigdrop", // apply css that makes the dropdown taller
    escapeMarkup: function (m) { return m; } // we do not want to escape markup since we are displaying html in results
});

There was made some changes to the select2 events names (I think on v. 4 and later) so the '-' is changed into this ':'.
See the next examples:

$('#select').on("select2:select", function(e) { 
    //Do stuff
});

You can check all the events at the 'select2' plugin site: select2 Events

//when a Department selecting
$('#department_id').on('select2-selecting', function (e) {
    console.log("Action Before Selected");
    var deptid=e.choice.id;
    var depttext=e.choice.text;
    console.log("Department ID "+deptid);
    console.log("Department Text "+depttext);
});

//when a Department removing
$('#department_id').on('select2-removing', function (e) {
    console.log("Action Before Deleted");
    var deptid=e.choice.id;
    var depttext=e.choice.text;
    console.log("Department ID "+deptid);
    console.log("Department Text "+depttext);
});

For above v4

$('#yourselect').on("select2:select", function(e) { 
     // after selection of select2 
});

As per my usage above v.4 this gonna work

$('#selectID').on("select2:select", function(e) { 
    //var value = e.params.data;  Using {id,text format}
});

And for less then v.4 this gonna work:

$('#selectID').on("change", function(e) { 
   //var value = e.params.data; Using {id,text} format
});

It works for me:

$('#yourselect').on("change", function(e) { 
   // what you would like to happen
});

This worked for me (Select2 4.0.4):

$(document).on('change', 'select#your_id', function(e) {
    // your code
    console.log('this.value', this.value);
});