<%@ Register Assembly="Obout.Ajax.UI" Namespace="Obout.Ajax.UI.FileUpload" TagPrefix="obout" %>
<script type="text/JavaScript">
function onClientBeforeUpload(sender, args) {
$get(
"<%= label.ClientID %>").innerHTML =
"";
return true;
}
</script>
...
<asp:UpdatePanel runat="server" ID="UpdatePanel1"><ContentTemplate>
<obout:FileUpload OnClientBeforeUpload="onClientBeforeUpload" Accept="image/*"
ValidFileExtensions="jpeg;jpg;gif;tiff;png" MaximumTotalFileSize="10240"
Width="250px" runat="server" id="fileUpload1" BrowseFieldDescription="Images"
/>
<br /><asp:Button runat="server" ID="submit" Text="Upload files" /><br /><br />
<asp:Label runat="server" ID="label" Text="" />
</ContentTemplate></asp:UpdatePanel>