jQuery change event not firing for input field

You can programmatically force a change event via the trigger('change') method:

$('#elementID').trigger('change');

This assumes, of course, that $('#elementID') is _(still) bound to a change event...

Use something like this, it always works.

$(function() {
    $("#my_input").on("change paste keyup", function() {
       alert($(this).val()); 
    });
});