Binding List Box to Two Different Drop Down Boxes

[programmher]

I need to bind my list box to two different drop down boxes. How do I bind my second dropdown box so my list box is populated with the author's name selected from my lbAuthorsList like it does when authors are selected from the lbGenrelist?

My code:

asp:DropDownList runat="server" ID="lbAuthorsList" style="float:left;" 
        DataSourceID="AuthorsList" DataTextField="DisplayName" DataValueField="UserID" 
        onselectedindexchanged="AuthorsList_SelectedIndexChanged" 
        AppendDataBoundItems="True"  AutoPostBack="True"
        ontextchanged="AuthorsList_SelectedIndexChanged" >
         <asp:ListItem Text="Select Authors" Value="~Select Authors~" />    
</asp:DropDownList>   
     <asp:DropDownList runat="server" ID="lbGenreList" 
                 style="float:left;" DataSourceID="odsGenres" 
                 DataTextField="Authorame" DataValueField="AuthorName" 
                 onselectedindexchanged="genreList_SelectedIndexChanged" 
                 AutoPostBack="True" AppendDataBoundItems="true" 
        onprerender="btnSortData_Click">
   </asp:DropDownList>  
       <asp:ListBox runat="server" ID="lbAuthorNameList" DataTextField="AuthorName" 
            DataValueField="AuthorID" DataSourceID="Authors" SelectionMode="Multiple"  AppendDataBoundItems="true" /> 
 

  {
 
        lbAuthorsList.DataBind();
    }
 
      protected void genreList_SelectedIndexChanged(object sender, EventArgs e)
    {
 
    lbAuthorsList.DataBind();  
    }