How do I Correctly get the center of the screen

When i change the canvas size seems like the middle of the screen gets weird..

As you can see in the capx, when you create the tiledbackground it's right in the middle of the screen. But, if you create it after you switch the canvas size, it's not.

That's weird.. how can I fix this?

Controls:

Space bar create the big tiledbackground to see if it's centralized. If you press again, it's destroyed.

1 and 2 switch canvas size.

https://1drv.ms/u/s!Ai2wcz1Xix0ygbdKXw3GCNpObxU1rQ

I think this is the way to center things. (to me best knowledge)

https://www.dropbox.com/s/8jpw357l7zd7s ... .capx?dl=0

Had to change keys to something easy for me.

I think this is the way to center things. (to me best knowledge)

https://www.dropbox.com/s/8jpw357l7zd7s ... .capx?dl=0

Had to change keys to something easy for me.

That's it <img src="{SMILIES_PATH}/icon_e_smile.gif" alt=":)" title="Smile">

Thank you very much.