Yo no digo que no sea posible
Código HTML:
Ver original<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"> <meta http-equiv="content-type" content="text/html; charset=utf-8" />
<script type="text/javascript"> //<![CDATA[
function m_o(cual) {
var capas = new Array("campo1", "campo2", "campo3");
var cadenaL = document.getElementById(cual).value.length;
var i;
if(cadenaL != 0){
for(i in capas){
if(capas[i] != cual){
document.getElementById(capas[i]).disabled = true;
}
}
}else{
for(i in capas){
document.getElementById(capas[i]).disabled = false;
}
}
}
//]]>
<form action="#" method="post"> <input type="text" id="campo1" value="campo1" onkeyup="m_o('campo1');" /><br /> <input type="text" id="campo2" value="campo2" onkeyup="m_o('campo2');"/><br /> <input type="text" id="campo3" value="campo3" onkeyup="m_o('campo3');"/><br />
Saludos