how do i blit images underneath the entity layer?
As far as I know, this can't be done (except with sprites, maybe? I really haven't touched those much).
However, you can hack it.
After blitting whatever it is you want below the entities, run a loop that goes through all entities on the map (or on the screen, if you want to optimize a bit) and blit entity.frame[entity_id_here] on top of that.
So:

Blit(x,y,whatever,screen);


for(i=0; i<entities; i++)


	BlitEntityFrame(entity.x[i]-xwin, entity.y[i]-ywin, i, entity.frame[i], screen);


ShowPage();

... or something to that effect.

the blitting command is: blit(x,y,imagename,destimage);
i usually notice destimage is 'screen'
are there any other variables that can replace this?
It's simply an image. The destination image could be one you loaded with LoadImage, created with NewImage, or the 'screen'. 'screen' really is just an image that represents what will be sent to the monitor on the next refresh.
The reason you would want to blit to the screen usually, is that most commonly you just want whatever you're doing to show up right away.
But say you were creating an image dynamically, which you were to use several times, it would be much more efficient to create a new image (using NewImage), draw onto that, and then blit that new image onto screen whenever you wanted to use it.

Let me know if my rambling confused more than it helped, and I'll think of a better way to explain.


EDIT: Whoops, minor artifact from my reused code went in there, making very little sense.

Also (this may be what Interference22 was talking about, as I haven't looked at Sully yet...though I doubt it, from the way he described it) it is possible to blit at multiple points in the renderstring, as I understand. A renderstring like '12RE3R' will render once beneath the entities and once above everything. You'll have to take this into account when writing your rendering function, like so:

int RenderState=0;


void RenderStuff() {


  if(RenderState == 0) {


     // Blit the things that need to appear beneath


     // entities


     RenderState++;


  } else if(RenderState == 1) {


     // Blit the things that need to appear above


     // everything.


     RenderState = 0;


  }


}

If you plan to do a lot of this sort of thing then you might consider writing or using a rendering lib to handle different types of rendering that need to be done at different times. I believe I have a lib in the V3 utilities section that could be modified to handle multiple render layers with a little bit of work, but I forget the name and I'm in a hurry...gotta go.

10x peeps!! tat really helped! i dun remember how much time i spent trying 2 figure this thing out >_< finally the mysteries of the universe have been revealed :p

You can do that in vc ...
curmap.rstring='1,2,R,E,R';

k k
i think i figured it out

i have 2 do something like this

somefunction
for 1st layer
change to 12re
blit blablabla
end
for 2nd layer
change to 12er
blit blablabla
showpage
end

The layers in the 'LAYERS'-tab in the bottom right of maped3 are drawn in the order of the renderstring. From top to bottom.
You can move it up or down with those arrows in the same tab.

That's the way I always do it anyway...