Yes, that`s it. I thought maybe there was some pre-made script which unites pixels and quants in a whole what would be the most elegant solution to control coordinates. But this will do also. Thanks.

Can I ask one more thing:

It seems there is a lost workshop in Online Tutorial. You see, at the end of workshop21 there is a link "Next: Walking, collision, events", but it leads only to workshop22 - Local Variables.

Whether the "Lost Chapter" can be found somewhere?

I could use some more informations about the topics, especially collisions.