Fill Dropdownlist from Javascript

Hi, today we will learn how to fill Dropdownlist from Javascript here is how:-

function fill_dropdown_list()
{
   var main_ddl = document.getElementsById('<%=dropdownlist1.ClientId%>');
   var options = document.createElement('option');
  
   for(var i=1;i<=10;i++)
   {
       if(options!=null)
       {
         options.text = "Hello"+i;
         options.value = i;
        
         if(main_ddl!=null)
            main_ddl.options.add(options);
       }
   }
}

<asp:Button id="btn_fill_drpdown" Text="Fill Dropdown" runat="server" onClientClick = "fill_dropdown_list();"></asp:Button>