displaying loading calm while doing webrequest

i have symbol webform. clicking symbol an httpwebrequest during onclick eventuality handler. after ask duplicate response ask httpcontext.current.response send client.

this web ask take while (up 5 seconds, given it's generating report). during user denote anything going on, solely browser swell bar spinning ie idol (if they're controlling ie). i need loading indicator while happening.

i've attempted controlling javascript fires during button's onclick eventuality (using onclientclick) while works, i don't know out web ask finished. given only send response client, full postback doesn't happen.

i've attempted jacket symbol an updatepanel controlling updateprogress, nonetheless send response httpcontext.current.response response.end(), an blunder javascript, given response isn't good shaped (we're eventuality behind an comparison square user download).

since we're eventuality behind record users download, i don't wish pop-up removed window, given following ie they'd information bar patience download.

any ideas here?