I've created my own admin page in wp-admin folder using add_theme_page() function. How to pass variables from there to my blog? I mean what's the easiest way without arrays etc.
I've tried using "globals" but failed.
Thanks a lot.
Read the codex page on creating options pages, and let us know if you run into any specific issues. It has a complete copy/paste example you can monkey with.
If you're trying to avoid learning WordPress' options mechanisms in favor of a more generic custom php solution, I understand where you're coming from, but recommend learning to do it the right way. It'll be a couple hours investment, but it'll pay off over time. For reals.
I think this should help you get started