function disableSubscriptions(chk)
{
    function updateCheckboxes(node)
    {
        if(node.checked && chk.checked)
        {
            node.checked = false;
        }               
        if(node.disabled !== undefined)
        {  
            node.disabled = chk.checked;
        }
    }
    
    var chkList = document.getElementById(trSubscriptions);
    walkDom(chkList, updateCheckboxes);
}

function chkOptOut_OnClick(chk)
{
    if(chk.checked)
    {
        var proceed = confirm(globalOptOutMessage);
        if(!proceed)
        {
            chk.checked = false;
            return;
        }
    }
    var chkList = document.getElementById(trSubscriptions);
    if (chkList) {
        disableSubscriptions(chk);
    }
}