split screens in 2.8 Sorry for being so simple but i'm finding it really difficult to work out how to split screens and then rejoin them. 

so i grab the corner of a screen and drag it creates a new screen then i grab the corner again and sometimes it creates a new one and sometimes it merges them. 

I'm a bit confused about the controls.

I looked on the 2.8 manual and I think its a bit out of date as it looks the same as 2.79.

Any help is greatly appreciated
It is the same as in 2.79 only the corners now look different - if you click on a corner of one area and then start dragging it in the direction of itself then it splits, if you start dragging it in the direction of another area it joins them. I believe the design for these functions might still be worked on and I would not be surprised if it was made a bit more intuitive in the end.

You can also rightclick on the edge between two areas and choose Join.