Minecraft Launcher 1.0.10 Won't Let Me Click 'Play' When Loaded

When I downloaded Minecraft 1.6.1, about a week ago, it worked fine. then i started looking at texture packs and mods. i knew i had to download mcpatcher/ optifine to use hd texture/ resource packs, so i downloaded both.
i opened minecraft as instructed, and mcpatcher 1.6.2 still wouldn't load, i deleted it and tryed optifine hd 1.6.2, which didn't work, even with magic launcher. i deleted it. i didn't play minecraft yesterday but turned my computer on this morning, loaded the launcher and i couldn't click the 'play' button. i logged in and out around 50 times and still couldn't click 'play'. So, i deleted minecraft and downloaded it again, still wouldn't let me click 'play'.Also, wondering if deleting minecraft without backing up saves will erase all data on it