Question

There is a

 <input type="checkbox" name="option2" id="checkbox_3" value="3" />

I tried this code

<script type="text/javascript">
    $(document).ready(function () {
        $('input[id*="checkbox_"]').click(function () {
            alert('!!!');
        });
    });
</script>

but no success.

Any clue?

Thank you!

Answer 1

I guess you have not included jQuery.

Put this before (and outside of) your script tag

<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>