I want to do my own preloads, for my game, I don't know if I can not remove or hide the mark of Unity and create my own preload thanks for the help
With the free version of unity you can't hide the preloader, but if you are savy at web page development you could create your own preloader in say flash and once your game has loaded the first level switch your unity game and the flash preloader positions on the page. But hey, if you're using the free version you should support the unity brand in some way at least.
You can append your own preloader after the one of Unity. If you create your webbuild with the option "streamed" Unity will stream your project scene by scene. The game will start right after the first scene is loaded completely. So the unity loading bar will just indicate the progress of your first level. The loading order is specified at the build settings dialog. Keep your first level small so that it loads quickly. Use `Application.GetStreamProgressForLevel` to get the progress for each level and make sure it's loaded before you use `LoadLevel` on them. Use can use `Application.CanStreamedLevelBeLoaded` to check whether you can load a particular level or not.
All that can be done in the free version of unity (and of course pro).