Problem is solved. It was about asynchronous communication via GDownloadUrl(), for loop was executed before all data was retrievec by GDownloadUrl() function.
I found. Sory, the topic should be deleted
I made my own is_page() function but didn’t overload the built-in one, it is why it didn’t work 😉
It’s good idea too. But what about the first question? Why doesn’t it work?