how to reinstall after a clean install

[jordan eff]

Hi guys

I downloaded lion and performed a clean install but just after i relised the Lion download was gon so I went to the app store to download it to keep it just incase i needed to do another install but it just says installed in the app store, how do I get it again if the app store won't let me download?

Thanks

 

[angelwatt]

This Apple page covers the details.
Option+click on it.