<asp:HiddenField ID="IsSelected" runat="server" />

    window. Onload = function() 
        {
          var IsSelected= Dom.get("FieldControl_emails_0_IsSelected");
           
           if((IsSelected !='undefined'))
              IsSelected.value='True'
            
            var isBlankRadioButton = Dom.get("IsBlankRadioButton");
            var isNotBlankRadioButton = Dom.get("IsNotBlankRadioButton");
            if(isBlankRadioButton !='undefined' || isBlankRadioButton. Checked ||(isNotBlankRadioButton != 'undefined' || isNotBlankRadioButton. Checked))
                
        };

Can anyone help me out to resolve the issue