Multiple scripts running at the same time?

Is there a way to have multiple scripts successfully running at the same time?

At the moment if I start a second script while the first one is still running, the second one completes successfully but the first one stops. This seems to be because the first one is no longer the active document once the second one opens so can't continue.

Is there another way to script things like this so that multiple can run independently at the same time? You might ask why I'd want to run two at the same time and not just wait, but i've setup an asp.net web form front end and having problems if two people click the button around the same time.

I'm guessing this isn't going to be possible and i'm going to have to look for ways of doing this in asp.net instead and somehow queue the requests so you have to wait longer if the script is already running?

Thanks,

Andy