// check whether a radio button option of a group has been selected
// var options = '<%=rblObject.ClientID %>';
// var bool = options.isRadioSelected();
String.prototype.isRadioSelected = function() {	
    var options = document.getElementById(this).getElementsByTagName('input');
    for(i=0;i<options.length;i++)
    {
        var opt = options[i];
        if(opt.type=="radio")
        {
            if(opt.checked)
            {
                return true;        
            }
        } 
    }
    return false;
}
// check whether a dropdownlist option has been selected - assuming that index 0 is not a valid option
// var options = '<%=ddlObject.ClientID %>';
// var bool = options.isRadioSelected();
String.prototype.isDropDownListSelected = function() {	
    var ddl = document.getElementById(this);
    return ddl.selectedIndex > 0;
}