how to email validation in javascript

<asp:TextBox ID="txtEmailID" ClientIDMode="Static" runat="server" CssClass="Email"                      ></asp:TextBox>

$(".Email").bind('change', function (event) {

        var testEmail = /^[A-Z0-9._%+-]+@([A-Z0-9-]+\.)+[A-Z]{2,4}$/i;

        if (testEmail.test($(this).val()))

            $(this).css('border', '1px solid silver');

        else {

            alert('Please Enter valid email');

            $(this).css('border', '1px solid red');

            $(this).val("");

            $(this).focus();

            return false;

        }

    });