First of all, thanks for the positive replies guys!
LavaWave, thanks alot.
nowon Actually no, it has nothing to do with the letters but that's a nice idea I will consider.
CrudeMik thank you very much. Yes, it loads the next level while climbing the ladder. Besides the special bonus screens which contain special event handling, every stage is loaded into the same layout.
<img src="http://up203.siz.co.il/up1/hndmymmmlnj2.png">
After the player finishes the level, when he reaches the X in the drawing, he is transfered back down and the next level is loaded. The levels are saved in external files.
And using many layouts is sometimes efficient: In game with predetermined environments, such as Point & Click, exploration games, RPGs, and such, it is not such a bad idea to use different layouts for each area. But in arcade games or more simple ones, with simple or dynamic levels, creating a map syntax for loading maps off external files is prefered. In my case I use the latter, but in another game I used to work on (a failure of an exploration-platformer) I used a different layout for each and every environment, with a couple of core spritesheets for inclusion.