Mouse not found error

I am trying to do two different set-ups. I tried both of these projects.

First I tried

And I keep getting an error ‘Mouse’ not found. Does your sketch include the line ‘#include <Mouse.h>’?

Next I tried this

And again I get the same error.

I am assuming it is something obvious, but I am a newbie.

You're not giving us much to go on there.

What type of Arduino board are you trying to use? Have you read that top line in the Harware Required section?

Sorry about that.

I am using a Leonardo board.

Post the exact code you used (copy and paste out of the IDE where you did it) and copy and paste the exact error message it gave you.

Please use code tags when you post code. If you don't know what that means, then find one of the "How to use this forum" posts at the top of any of the boards and read through that.