function disable_radio(id)
{
var radiobox= document.getElementById(id);
radiobox.disabled=true;
radiobox.checked=false;
var text = document.getElementById('t'+id);
text.style.color = "#CCC";
}

function enable_radio(id)
{
var radiobox= document.getElementById(id);
radiobox.disabled=false;
var text = document.getElementById('t'+id);
text.style.color = "#000";
}