In order to stop the repeating of command, onebang is added to only play once after its bang. Sel done is add to reset onebang after the whole clip is being played.
Message exportimage jpeg
This message was really simple however, it took me for about 1 hours to find out how it works. But it was really fulfilling that i manage to solve it my own!
When a person are in frame [if($i1>=3000) then bang) was to delay it for 3 seconds before it send bang to export the image.