$(document).ready(function() {
    $("#TellAFriend").submit(function() {
        var f = $("#TellAFriend");
        var action = f.attr("action");
        var serializedForm = f.serialize();
         // validate Your name
        var UserName = document.getElementById("UserName").value;
        // validate FriendEmail
        var FriendEmail = document.getElementById("FriendEmail").value;

        if (UserName == "") {
            alert("Please enter your name ");
            document.getElementById("UserName").focus();
            return false;

        } else if (FriendEmail == "") {
            alert("Please enter valid email address of your friend.");
            document.getElementById("FriendEmail").focus();
            return false;
        } else {

            $.post(action,
        serializedForm,
        function () { alert("Thanks. Your friend has been emailed."); });
        }
        return false;
        jQuery().ajaxStart(function() {
            $("#TellAFriend").fadeOut("slow");
        });
        jQuery().ajaxStop(function() {
            $("#TellAFriend").fadeIn("fast");   
        });
    });
});