focus از یک Textbox به Textbox دیگری

کد html





<html xmlns="http://www.w3.org/1999/xhtml">

<head runat="server">

    <title></title>

    <script>

            function changeFocus(from, to,number) {





            if (document.getElementById(from).value.length == number) {



                document.getElementById(to).focus();

            

            }

        }

    </script>

</head>

<body>

    <form id="form1" runat="server">



    <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>

    <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>

<asp:TextBox ID="TextBox3" runat="server"></asp:TextBox>



    </form>

</body>

</html>

کد سمت سرور :



    protected void Page_Load(object sender, EventArgs e)

    {

      

        TextBox1.Attributes.Add("onkeyup", "changeFocus('" + TextBox1.ClientID + "','" + TextBox2.ClientID + "',3);");

       TextBox1.Attributes.Add("onkeydown", "changeFocus('" + TextBox1.ClientID + "','" + TextBox2.ClientID + "',3);");

      

       

       TextBox2.Attributes.Add("onkeyup", "changeFocus('" + TextBox2.ClientID + "','" + TextBox3.ClientID + "',6);");

        TextBox2.Attributes.Add("onkeydown", "changeFocus('" + TextBox2.ClientID + "','" + TextBox3.ClientID + "',6);");

    }

موفق باشی