jqueryチェック

<input id="Text1" type="text" /><span id="Text1Note"></span><br />
        <input id="Text2" type="text" /><span id="Text2Note"></span><br />
        <input id="Text3" type="text" /><span id="Text3Note"></span><br />
        <input id="Text4" type="text" /><span id="Text4Note"></span><br />
        <input id="Button1" type="button" value="button" onclick="return onsumbit()" />
        <script>
            //     1 3    
            //focusin       ，focusout     
            $("#Text1").focusin(function () {
                $("#Text1Note").html("   1      ！");
            }).focusout(function () {
                if ($("#Text1").val() == "")
                    $("#Text1Note").html("   1      ！");
                else
                    $("#Text1Note").html("");
            });

            $("#Text3").focusin(function () {
                $("#Text3Note").html("   3      ！");
            }).focusout(function () {
                if ($("#Text3").val() == "")
                    $("#Text3Note").html("   3      ！");
                else
                    $("#Text3Note").html("");
            });
            //                
            function onsumbit() {
                if ($("#Text1").val() == "")
                    $("#Text1Note").html("   1      ！");
                if ($("#Text3").val() == "")
                    $("#Text3Note").html("   3      ！");
                return false;
            }
        </script>