Código HTML:
<script languaje="javascript"> function habilita(form) { form.cat_al[1].disabled = false; form.cat_al[2].disabled = false; form.cat_al[3].disabled = false; form.cat_al[4].disabled = false; } function deshabilita(form) { form.cat_al[1].disabled = true; form.cat_al[2].disabled = true; form.cat_al[3].disabled = true; form.cat_al[4].disabled = true; } </script> <FORM name="form1" ACTION="Insert.php" METHOD="POST"> <input type="radio" name="res" value="1" checked onClick="habilita(this.form)" /> <input type="radio" name="res" value="0" onClick="deshabilita(this.form)" /> <input type="checkbox" name="cat_al[1]" value="1"/> <input type="checkbox" name="cat_al[2]" value="2"/> <input type="checkbox" name="cat_al[3]" value="3"/> <input type="checkbox" name="cat_al[4]" value="4"/> </FORM>