Add remove readonly attribute to TextBox based on CheckBox change event using jQuery in ASP.Net
<html xmlns="http://www.w3.org/1999/xhtml">
<head> <title></title> <script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script> <script type="text/javascript"> $(document).ready(function () { $("#chkRead").change(function () { if ($(this).is(":checked")) { $('#txtFaisalaId').removeAttr("readonly") } else { $('#txtFaisalaId').attr('readonly', true); } }); }); </script></head><body> <div> <input id="chkRead" type="checkbox" name="chkRead" /><label for="chkRead">Test</label> <input name="txtFaisalaId" type="text" readonly="readonly" id="txtFaisalaId" /> </div></body></html>