<script type="text/javascript"> var IsEmail=function () { var email=$('#quip-comment-email-qcom').val(); var regex = /^([a-zA-Z0-9_\.\-\+])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/; if (regex.test(email)==false) { $('button[name="quip-post"]').attr("disabled","yes"); } else { $('button[name="quip-post"]').removeAttr("disabled"); } } $('#quip-comment-email-qcom').bind('keydown keypress', function () { setTimeout(function() { IsEmail(); }); }); </script>