"I have the same problem on the brand new laptop I bought yesterday, idk what to do" <--- that is not an answer. So lets try a few things.
first,
Were you trying to make any edits? ie mods? Some times when this happens in the mod case, most users forget to delete the folder called "Meta.inf"
Press the windows logo + r and type in %appdata%
After that, look for .minecraft, then bin, then use winRAR on minecraft.jar
When your in that folder, simply delete the Meta.inf folder.
If this is NOT the case there are still some other ideas to try.
1) try uninstalling and reinstalling minecraft.
2) try a different browser.
3) try the download client.
To go full screen in Minecraft, you press F11. (Not sure if it works on Mac, but it probably does)
Webpages are displayed in your browser. Use the controls on your browser to display more on the screen. If you click the restore up button on the browser, you will open your browser as far as it will go. If you want to see the webpage without the browser menus, etc. you will need to use the options available on your browser. The F11 key will toggle the full screen view with Internet Explorer.
The one in your browser tends to use less ram but lags more, and is in a smaller window. Edit-Actually the difference is minimal the downloaded version you can mod on the using the Minecraft forum there is a ton of texture mods to improve the visual quality. Doku Rpg, John Smith and Mixcraft are my 3 favs. Also if you decide to use the browser version you can simply hit F11 to full screen it.
print screen key on keyboard, if you have steam, you can run minecraft from your library and use the steam screenshot system.
Minecraft Forge lists you all mods in minecraft and Forge
Black screen.
Fps...........
You can'nt
To do split screen in the Xbox360 edition, minecraft mandates that the user has an HD tv.
Yes, there is split screen on Minecraft Xbox 360 Edition, but it is exclusively for the use of HDTVs, so far.
You can press F11 to make browser go to full screen. To exit, press F11 again and it brings itself to default.
Simply login in launcher screen(need premium) and you can play. enjoy!