How do I create an apk file

Ok, so I want to build my game into an apk, to test if everything works correctly, but when I tried to build the apk, it asks me for the root folder of Android SDK, so I went and downloaded the latest version, and it wasn’t working. After that I found out that the latest version is not working properly and I need another version (I think they said r21 or below) so I downloaded it, after days of searching. It accepted the root folder and then it asks me for API 14 as a minimum. I click the update button that showed up in Unity and it’s stuck there. Then I go into the SDK Manager and try to find the API 14, but there is nothing like that, and anything I try to install it simply doesn’t install it… Any ideas?

Ok, first of all, I can’t see the previous answer, but I came to a succesful apk creation with the latest version of the ADT bundle, in the adt.something… there are three files, eclipse, sdk and SDK Manager, I selected the sdk folder and it worked. Now, how do I close this question with a [SOLVED] at the end of the title?