Hola
susaninhax
Prueba esto:
Código PHP:
<html>
<head>
<script type="text/javascript">
function habilita(obj) {
numSele = 3;
for (i=0; i<numSele; i++)
document.forms[0]['sele'+i].disabled = (obj.value != i);
}
</script>
</head>
<body>
<form>
<input type="radio" name="rad" value="0" onclick="habilita(this)">
<select name="sele0" disabled="disabled">
<option>---</option>
</select><br />
<input type="radio" name="rad" value="1" onclick="habilita(this)">
<select name="sele1" disabled="disabled">
<option>---</option>
</select><br />
<input type="radio" name="rad" value="2" onclick="habilita(this)">
<select name="sele2" disabled="disabled">
<option>---</option>
</select>
</form>
</body>
</html>
Saludos,
