How to detect when a text input changes with ie8

I want to detect when a text input changes. I tried these, which worked in firefox but not in ie 8.

$('#taskSearch').bind('input', function() {
     alert($(this).val());
});
$('#taskSearch').live('input', function() {
    alert($(this).val());
});
$('#taskSearch').change(function() {
    alert($(this).val());
});