How to call NeroDrive.EstimateTrackSize

i am writing VCD burning program.I am using nerocom and vb6

for that i create nerovideoitems and call BurnVCD2 funcion with the nerovideoitems

I would like to estimate the track size of the the VCD and display on top of the progress window.

I tried calling NeroDrive.EstimateTracksize but it gives an error saying that an asynchchronous operation is going on and cannot call the function now

for calling nerodrive.estimatetracksize i use the ISOtrack argument i passed to BurnVCD2 method

Can anyone please give me the exact sequence of calling this function.I tried calling it in onprogress but it did not work.

IS there anyway to work the same with image recorder

Thanks before hand