I develop file upload control based on ext:FileUploadField. It can shows the list of uploaded files, a last error and delete uploaded files. It can do without postback.
Maybe anybody suggest me ready solutions? If don't, which approach I must to use to do it? Update panel from ajax toolkit? ext:Store? Or what?

    <ext:FormPanel ID="BasicForm" runat="server" Width="500" Frame="true" Title="File upload"
        AutoHeight="true" MonitorValid="true" PaddingSummary="10px 10px 0 10px" LabelWidth="50">
            <ext:Parameter Name="anchor" Value="95%" Mode="Value" />
            <ext:Parameter Name="allowBlank" Value="false" Mode="Raw" />
            <ext:Parameter Name="msgTarget" Value="side" Mode="Value" />
            <ext:FileUploadField ID="FileUploadField1" runat="server" EmptyText="Choose a file"
                FieldLabel="file" ButtonText="" Icon="ImageAdd" />
            <ClientValidation Handler="#{SaveButton}.setDisabled(!valid);" />
            <ext:Button ID="SaveButton" runat="server" Text="Загрузить">
                    <Click OnEvent="UploadClick"></Click>