App inventor 2 help with blocks for buttons please.

I have a canvas that shows a university campus which has a ball on each building, i would like to create a code where i can click on the ball and at the top of the screen it shows the amount of computers available in each building, and then i need to create a cancel button that adds 1 to the computers available but can only be clicked if you click reserve first, and also a reserve button which takes away 1 from the computers available. I am having great difficulty doing this and would really appreciate any help. I find the blocks way too hard to do because i have not used or been taught about this software at all. :(

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 I find the blocks way too hard to do because i have not used or been taught about this software at all.

A very good way to learn App Inventor is to read the free Inventor's Manual here in the AI2 free online eBook   http://www.appinventor.org/book2 ... the links are at the bottom of the Web page.  The book 'teaches' users how to program with AI2 blocks.

There is a free programming course here http://www.appinventor.org/content/CourseInABox/Intro  and the aia files for the projects in the book are here:  http://www.appinventor.org/bookFiles  

How to do a lot of basic things with App Inventor are described here:  http://www.appinventor.org/content/howDoYou/eventHandling  .

Also do the tutorials http://appinventor.mit.edu/explore/ai2/tutorials.html to learn the basics of AppInventor, then try something and follow the

 Top 5 Tips: How to learn App Inventor

You will not find a tutorial, which does exactly what you are looking for. But doing the tutorials (not only reading a little bit) help you to understand, how things are working. This is important and this is the first step to do.

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