//validate at least 1 rdo button is selected.

//for a group of radio buttons, or an rdo list control
// eg:    var sGroup = "ctl00_cp_rdoSlider";
//        var iRadios = 3;  (where buttons' ids are ctl00_cp_rdoSlider0 ctl00_cp_rdoSlider1 and ctl00_cp_rdoSlider2
function rdoIsSelected(sGroup, iRadios)
{
    for (var i = 0; i < iRadios; i++) 
    {
        var sID = sGroup + i;
        var ctrl = document.getElementById(sID);      
        if (ctrl.checked) {return true;}
    }
    return false;
}//rdoIsSelected

//return selected ID of rdo
function rdoSelectedID(sGroup, iRadios)
{
    for (var i = 0; i < iRadios; i++) 
    {
        var sID = sGroup + i;
        var ctrl = document.getElementById(sID);      
        if (ctrl.checked) {return sID;}
    }
    return false;
}//rdoSelectedID