Assume that your all control, set tabindex property
<div>
<asp:TextBox ID="txtID1" runat="server" TabIndex="0" MaxLength="2"></asp:TextBox>
</div>
<div>
<asp:TextBox ID="txtID2" runat="server" TabIndex="1" MaxLength="3"></asp:TextBox>
</div>
<div>
<asp:TextBox ID="txtID3" runat="server" TabIndex="2" MaxLength="2"></asp:TextBox>
</div>
Now your javascript code like as follows
$(function () {
$("input").keypress(function (evt) {
var element = $(evt.target);
var tabIndex = element.attr('tabIndex');
var input = element.val();
var maxLength = element.attr("maxLength");
var inputLength = input.length;
var charCode = (evt.which) ? evt.which : evt.keyCode;
if (8 == charCode)
return true;
if (inputLength+1 == maxLength) {
var nextElement = $("input[tabIndex=" + (parseInt(tabIndex) + 1) + "]");
if (nextElement) {
nextElement.focus();
}
}
});
});