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