Prueba este código haber si te funciona
Código HTML:
Ver original<!DOCTYPE html PUBLIC "-//WAPFORUM//DTD XHTML Mobile 1.0//EN" "http://www.wapforum.org/DTD/xhtml-mobile10.dtd">
<script type="text/javascript"> function disableDos() {
var field = formulario.dos
if (formulario.uno.checked) {
field.checked = false;
field.disabled = true;
formulario.wow.disabled = false;
formulario.wow2.disabled = true;
}
else{
field.disabled = false;
formulario.wow.disabled = true;
}
}
function disableUno() {
var field = formulario.uno
if (formulario.dos.checked) {
field.checked = false;
field.disabled = true;
formulario.wow.disabled = true;
formulario.wow2.disabled = false;
}
else{
field.disabled = false;
formulario.wow2.disabled = true;
}
}
<input type="checkbox" name="uno" onClick="disableDos()"/><br/> <input type="checkbox" name="dos" onClick="disableUno()"/><br/> <input type="text" name="wow" disabled> <input type="text" name="wow2" disabled>
En este enlace hay más información de disabled
http://fgualambo.blogspot.com/2011/10/la-propiedad-disabled-en-javascript.html