in reply to using 'my'
You may find some benefit in reading Use strict warnings and diagnostics for a brief
ode praising the benefits of being strict. This article is a couple of pages long. If you want
more detail there is a longer version as well. There are also links to all the detail you are
likely to want. I highly recommend the Mark-Jason Dominus article "Coping with scoping" which has
already been suggested to you.
When your two page app becomes 1500 lines of code you will be happy you made the effort!