jquery check if asp checkbox is checked
<p>Hello everyone I have a checkbox I want to check if its checked or no on client side, before postback happens. 
Here is the checkbox:</p>

<pre><code> &lt;asp:CheckBox runat="server" CssClass="checkbox" Checked="true" ID="checkboxRules" /&gt;
</code></pre>

<p>Thanks in advance, Laziale</p>

<p>UPDATE:
The problem is that there is a button on the page too which is triggered by js code, and maybe I can add a line there to check if the checkbox is checked once the button is clicked, otherwise display message for unchecked checkbox:</p>

<p>function enterClick() {
        $('#SUBMIT').click();
    }</p>

<pre><code>var ishown = false;
$(document).ready(function () {
    $('#BUTTON').click(function (e) {
</code></pre>

<p>//I want to put the checkbox logic here</p>

<p>Thanks again</p>
