Enable a button on check box checked without page refresh

In this tutorial I will show you how to enable a button on checking of a check box without using any update panel.  This is i found when I wanted to enable a register button in an registration form using update panel and the Css of the button was not working when it is disable.

So lets create a new project. And add a new check box and a button into a new web form.

<asp:CheckBox ID="chkTermsCondition" runat="server" Text="Check now"/></a>

<asp:Button ID="btnRegister" runat="server" Text="Register" 

onclick="btnRegister_Click" class="contact-button" />

Now in the head section add a java script code to do the action.

<script type="text/javascript" src="http://code.jquery.com/jquery-1.9.1.min.js">

</script>

<script  type="text/javascript" >

    $(function () {

        var $btn = $(":submit[id$=btnRegister]");

        var $chk = $(":input:CheckBox[id$=chkTermsCondition]");

        // check on page load

        checkChecked($chk);

        $chk.click(function () {

            checkChecked($chk);

        });

        function checkChecked(chkBox) {

            if ($chk.is(':checked')) {

                $btn.removeAttr('disabled');

            }

            else {

                $btn.attr('disabled', 'disabled')

            }

        }

    });

</script>

Add Jquery plugin to your project or add Google, Jquery online plugin. And now run the project and test. Enjoy...  :)