How to shoot a gun

I am trying to shoot the gun when the user clicks the button , but it’s not working . I posted this question earlier in the year and someone gave me a perfect example but when I went to my content I couldn’t find it . Can someone help me ?

The code I got previously was a square shooting mini squares when you touched the square or the screen 

https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=comeUp264+site:forums.coronalabs.com&start=30

Thanks a lot

https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=comeUp264+site:forums.coronalabs.com&start=30

Thanks a lot