Ajax File Upload Help Required

I am using Ajax File upload control . When i click the button upload the page gets postback and property Page.isPostback gets false and the code which should be executed on first time page load is executed again. Is there solutuon of this problem  on clicking upload button of ajax file upload.

Here i share my code 

if (!this.IsPostBack) {Do_Page_Load_Settings();}  // this condition is true on first time page load but when upload button of ajaxfile upload

is clicked this condition gets again true. How to avoid it

<div id="CFileUploaderMain" class="FileUploaderMain" style="display:none;">

<asp:AjaxFileUpload ID="AjaxFileUpload1" runat="server" OnUploadComplete="AjaxFileUpload1_UploadComplete" ThrobberID="ImgLoader" MaximumNumberOfFiles="10" AllowedFileTypes="tiff,docx,msword,txt,bmp,jpg,jpeg,png,gif,tif,pdf,plain,vnd.openxmlformats-officedocument.wordprocessingml.document,exe" OnClientUploadComplete="UploadCompleted" OnClientUploadError ="UploadNotCompleted" />
<asp:Image ID="ImgLoader" runat="server" ImageUrl="~/Images/ajax-loader.gif" Style="display:None" />

</div>

Waiting ur response.

Regards,

Irfan