Email Address Validation @ is not working cshtml

Question

$('#pin_Email').keypress(function (e) {

var regex = new RegExp("^([a-zA-Z0-9]+)@([a-zA-Z0-9]+)\.([a-zA-Z]{2,5})$");

var str = String.fromCharCode(!e.charCode ? e.which : e.charCode);

if (regex.test(str)) {

return true;

}

else {

e.preventDefault();

return false;

}

});