function SelectionMade(source, clientside_arguments)
{ 
    var checkBoxName = source.getAttribute('TargetControlId');
    var isValid = false;
    var chkArray = document.getElementsByTagName('input');
    
    for(i=0;i<chkArray.length;i++)
    {
        var chkName = chkArray[i].name.substring(10,31);
        if (chkName == checkBoxName)
        {
            if(chkArray[i].checked)
                isValid = true;
        }
    }        
    
    if(!isValid && typeof(HideServerFeedback == "function"))
    {
        HideServerFeedback(source.validationGroup);
    }
    
    clientside_arguments.IsValid = isValid;
}