C# - Asyncfileupload Show Image After Upload Without Refreshing The Page

I have been cracking at this for a while now with no luck.

Using asyncfileupload control to upload a file and display the image. The uploading works fine and image is displayed if I reload/refresh the page.

But need to know how I can do this without reloading/refreshing the page.

After reading online posts, I see a recommendation to use scriptmanager but this doesn't work for me:

protected void FileUploadComplete(object sender, AjaxControlToolkit.AsyncFileUploadEventArgs e)
{
ScriptManager.RegisterStartupScript(this, GetType(), "TestAlert",
"window.parent.document.getElementById('" + img_ProfilePic.ClientID + "').src='" + "http://www.site.com/default.jpg" + "');",
true);
}