I tried to download OS/X Mavericks through the App Store yesterday. However, I had to leave work before it was done downloading and shut down the machine while it was downloading.

I assumed I'd be able to resume the download, or start over again later.

However, now there's no way to get it to download again. When I find OS/X Mavericks in the store, I click on the "Download" link. It asks for my Apple ID which I enter, and it does absolutely nothing. It doesn't begin downloading, and it just still shows the "Download" button. Clicking on it again does nothing.

I'm thinking there's something stuck somewhere, like some flag that says this download is in progress or it has already been downloaded. Is there some way to clear that out so I can start downloading it again?