用JQuery怎么去一次性获取 aspTextBox 文本框的值

如：
<asp:TextBox ID="txtSubject" runat="server">aa</asp:TextBox>

第一次用服务器控件，原来他就是和input标签一样！

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <script type="text/javascript" src="script/Jquery.js"></script>
    <script type="text/javascript">
        $(function () {
            var str="";
            var t1=document.getElementById("<%= TextBox1.ClientID").value;
            var t2=$("#<%= TextBox1.ClientID%>").val();
            alert(t1);
            alert(t2);
        })
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <asp:TextBox ID="TextBox1" runat="server">sdf</asp:TextBox>
    <asp:TextBox ID="TextBox2" runat="server">sdf</asp:TextBox>
    <asp:TextBox ID="TextBox3" runat="server">ee</asp:TextBox>
    <asp:TextBox ID="TextBox4" runat="server">ee</asp:TextBox>
    <asp:TextBox ID="TextBox5" runat="server">ee</asp:TextBox>
    <input type="button"  name="button" value="button"/>
    </form>
</body>
</html>