[JavaScript][HTML]wartość disabled Opcje

[bluebird]

Witam

[HTML] pobierz, plaintext 
 
tak<input type="radio" name="yes" id="yes" value="y" onclick="if(document.getElementById('yes').value=='y'){document.getElementById('nafa_c').disabled=false;document.getElementById('kf_c').disabled=false;document.getElementById('ffs_c').disabled=false;document.getElementById('seattle_c').disabled=false;}"/>
 
nie<input type="radio" name="yes" id="yes" value="n" onchange="if(document.getElementById('yes').value=='n'){document.getElementById('nafa_c').disabled=true;document.getElementById('kf_c').disabled=true;document.getElementById('ffs_c').disabled=true;document.getElementById('seattle_c').disabled=true;}"/>
 
<input type="checkbox" name="nafa_c" id="nafa_c"disabled="disabled"/><input name="nafa" id="nafa" disabled="disabled"/>
<input type="checkbox" name="kf_c" id="kf_c" disabled="disabled"/><input name="kf" id="kf" disabled="disabled"/>
<input type="checkbox" name="ffs_c" id="ffs_c" disabled="disabled"/><input name="ffs" id="ffs" disabled="disabled"/>
<input type="checkbox" name="seattle_c" id="seattle_c" disabled="disabled"/><input name="seattle" id="seattle" disabled="disabled"/>
[HTML] pobierz, plaintext 

w tym wypadku wybierajac radio tak checkboxy są enabled ale przy wyborze radio nie checkboxy nie robią się disabled. kto pomoże?