you may have discovered that working on layer1 can be very unforgiving, Any editing you do on that layer1 means clicking a lot of brushsmaybe...

 I show you now how to work with any count of objects, very easy.

 - brought to you by: Noire_Brute_Force(GER)

1: Press "L" to open the Layers menü. Make a right click. in that window. and  

    chose "Add Layer ->New" Give it a good name, for,

2: In the Layer Window , U can see the name of your Layer

   and  "A, V, S" (I marked it on the image RED)

   A: stands for the active Layer, every editing you do will be saved in 

        that Layer.

   V: Stands for Visible, if u uncheck this, the hole Layer isnt visible.

        But still compiled!

    S: I realy dont know, i might saving but wasnt. maybe someone can add...

You can make a right click on every layer and choose to Select Hole Layers.

Means Full houses. Hole parts of your map. 

That allows u to work on small parts from big maps in a clear map file. U just have to save the layer and load in in your main map. 

I Hope That small TUT, helps someone.!