Hola otra vez:
Prueba esto:
Código PHP:
<html>
<head>
<script language="JavaScript">
<!--
function actualizar() {
var losRadio = document.forms.entrada.radio1;
for (var i = 0; i < losRadio.length; i ++)
document.forms.entrada[losRadio[i].value].disabled = (losRadio[i].checked == true) ? false : true;
}
function ini() {
var losRadio = document.forms.entrada.radio1;
for (var i = 0; i < losRadio.length; i ++) {
document.forms.entrada.radio1[i].onclick = actualizar;
document.forms.entrada[losRadio[i].value].disabled = (i == 0) ? false : true;
}
document.forms.entrada.radio1[0].checked = true;
}
//-->
</script>
</head>
<body onload=ini()>
<form>
<fieldset>
<legend>
Valores
</legend>
Valor 1 <input type=radio name="radio1" value="A0"><input type=text name="A0">
Valor 2 <input type=radio name="radio1" value="A1"><input type=text name="A1">
Valor 3 <input type=radio name="radio1" value="A2"><input type=text name="A2">
Valor 4 <input type=radio name="radio1" value="A3"><input type=text name="A3">
</fieldset>
<br>
</form>
</body>
</html>
Saludos