var TabArr = new Array();
//TabArr["AGN"] = [4, "CTA"];
//TabArr["CTA"] = [7, "DIGCTA"];
//TabArr["DIGCTA"] = [1, "Entra"];
var prevlength = 0;
var prevname = "";
function handKeydown(e)
{
	var campo;
	if(document.all)
		campo = window.event.srcElement;
	else
		campo = e.target;
	if(campo.name){
		prevlength = campo.value.length;
		prevname = campo.name;
	}
}
function handKeyup(e)
{
	var campo;
	if(document.all)
		campo = window.event.srcElement;
	else
		campo = e.target;
	if(campo.name && TabArr[campo.name]){
		if(	(campo.value.length >= TabArr[campo.name][0]) && 
			(campo.value.length > prevlength) &&
			(campo.name == prevname) &&
			campo.form.elements[TabArr[campo.name][1]]){
			campo.form.elements[TabArr[campo.name][1]].focus();
			prevname = campo.form.elements[TabArr[campo.name][1]].name;
		}
	}	
}
window.document.onkeyup = handKeyup;
window.document.onkeydown = handKeydown;
if(document.layers)
	window.document.captureEvents(Event.KEYUP | Event.KEYDOWN)