[gears-users] Error in ProgressEvent class

[amit malviya]

function getData1() {

                                var request = 
google.gears.factory.create('beta.httprequest');

                                request.open('GET',url for zip file');

                                request.onprogress = function 
onprogress(progressEvent){
                                            var percent = (progressEvent.loaded 
/ progressEvent.total) *
100;
                                            var displaySpan =
document.getElementById("progress_status");
                                            displaySpan.innerHTML = percent + 
'%'
                        }
                                request.onreadystatechange = function() {
                                  if (request.readyState == 4) {
                                        //some code here............
                                  }
                                }

                                request.send();
                        }

In this function, the onprogress event is calling only 2 times.. one
is at time 0 and another is 100.
its not giivng proper value slot like 0,10,15,20..... 100.

please reply me if any have suggestions/answer.

Amit