AjaxFileUpload dialog box - cant select multiple files

vs express 2012

targetFramework="4.0"

IE10

install ajax toolkit via manage nuGet packages for solution - and tried to reinstall it...

the prob: 

on dialog box - cant select multiple files... just one at the time.

i would like to have the same behavior like in the ajax control tool kit oficial page..

add in web.config:

<system.webServer><validation validateIntegratedModeConfiguration="false"/><handlers><add name="AjaxFileUploadHandler" verb="*" path="AjaxFileUploadHandler.axd" type="AjaxControlToolkit.AjaxFileUploadHandler,            AjaxControlToolkit"/></handlers></system.webServer>

<form id="form1" runat="server"><asp:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server"></asp:ToolkitScriptManager><div><asp:Label runat="server" ID="myThrobber" Style="display: none;"><img align="absmiddle" alt="" src="images/uploading.gif"/></asp:Label><asp:AjaxFileUpload ID="AjaxFileUpload1" runat="server"
                OnUploadComplete="AjaxFileUpload1_UploadComplete" 
                ThrobberID="myThrobber" MaximumNumberOfFiles="10" AllowedFileTypes="jpg,jpeg,gif" /></div></form>

protected void AjaxFileUpload1_UploadComplete(object sender, AjaxControlToolkit.AjaxFileUploadEventArgs e)
    {
        //string filePath = "~/upload/" + e.FileName;
        //AjaxFileUpload1.SaveAs(filePath);

    }