Good day...! In the code behind (upload.aspx) I have an event that returns the number of bytes being streamed; and as I debug it, it works fine. I wanted to reflect the numbers returned from the eventHandler on a progress bar and this is where I got lost. I tried using jQuery's .ajax() function. this is how I implemented it: In the EventHandler in my code behind I added this code to call the .ajax() function: Page.ClientScript.RegisterStartupScript(this.GetType(), "UpdateProgress", "<script type='text/javascript'>updateProgress();</script>"); My plan is whenever the eventHandler function changes the values of bytes being streamed it calls the javascript function "updateProgress()" The .ajax() function "UpdateProgress()" is as: function updateProgress() { $.ajax({ type: "POST", url: "upload.aspx/GetData", data: "{}", contentType: "application/json; charset=utf-8", dataType: "json", async: true, success: function (msg) { $("#progressbar").progressbar("option", "value", msg.d); } }); } I made sure that the function GetData() is [System.Web.Services.WebMethod] and that it is static as well. so the workflow of what I am trying to implement is as: - Click On Upload button - The Behind code starts executing and EventHandler triggers - The EventHandler calls .ajax() function - The .ajax() function retrieves the bytes being streamed and updates progress bar. When I ran the code; all runs well except that the .ajax() is only executed when upload is finished (and progress bar also updates only when finished upload); even though I call .ajax() function every time in the eventHandler function as reflected above... What am I doing wrong? Am I thinking of this right? is there anything else I should add maybe an updatePanel or something? thank you